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Volume 17, Number 21,
Issue of November 1, 1997
pp. 8246-8258
Copyright ©1997 Society for Neuroscience
Association and Colocalization of the Kv
1 and Kv
2
-Subunits with Kv1
-Subunits in Mammalian Brain K+
Channel Complexes
Kenneth J. Rhodes1,
Brian W. Strassle1,
Michael
M. Monaghan1,
Zewditu Bekele-Arcuri2,
Maria F. Matos2, and
James S. Trimmer2
1 Central Nervous System Disorders, Wyeth-Ayerst
Research, Princeton, New Jersey 08543, and 2 Department of
Biochemistry and Cell Biology and Institute for Cell and Developmental
Biology, State University of New York, Stony Brook, New York 11794
ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
FOOTNOTES
REFERENCES
ABSTRACT
The differential expression and association of cytoplasmic
-subunits with pore-forming
-subunits may contribute
significantly to the complexity and heterogeneity of voltage-gated
K+ channels in excitable cells. Here we examined the
association and colocalization of two mammalian
-subunits, Kv
1
and Kv
2, with the K+ channel
-subunits Kv1.1,
Kv1.2, Kv1.4, Kv1.6, and Kv2.1 in adult rat brain. Reciprocal
coimmunoprecipitation experiments using subunit-specific antibodies
indicated that Kv
1 and Kv
2 associate with all the Kv1
-subunits examined, and with each other, but not with Kv2.1. A much
larger portion of the total brain pool of Kv1-containing channel
complexes was found associated with Kv
2 than with Kv
1. Single-
and multiple-label immunohistochemical staining indicated that Kv
1
codistributes extensively with Kv1.1 and Kv1.4 in cortical
interneurons, in the hippocampal perforant path and mossy fiber
pathways, and in the globus pallidus and substantia nigra. Kv
2
codistributes extensively with Kv1.1 and Kv1.2 in all brain regions
examined and was strikingly colocalized with these
-subunits in the
juxtaparanodal region of nodes of Ranvier as well as in the axons and
terminals of cerebellar basket cells. Taken together, these data
provide a direct demonstration that Kv
1 and Kv
2 associate and
colocalize with Kv1
-subunits in native tissues and provide a
biochemical and neuroanatomical basis for the differential contribution
of Kv1
- and
-subunits to electrophysiologically diverse neuronal
K+ currents.
Key words:
ion channel;
central nervous system;
cerebellum;
striatum;
immunoprecipitation;
immunohistochemistry;
immunofluorescence;
epilepsy
INTRODUCTION
All excitable cells express
voltage-gated K+ channels. These channels are
critical for a wide variety of processes, including action potential
propagation and lymphocyte activation, and play an essential role in
neurons where they regulate the resting membrane potential, impact
dendritic excitability, control the frequency and duration of action
potentials, and modulate neurotransmitter release (Hille, 1992
). Recent
work in several laboratories has determined that K+
channels are integral membrane, hetero-oligomeric glycoprotein complexes composed of four pore-forming
-subunits and four
cytoplasmic
-subunit polypeptides (for review, see Pongs, 1995
; Jan
and Jan, 1997
). Although it has been appreciated that the association
of functionally distinct
-subunits contributes to the tremendous diversity of K+ channel types observed in native
cells (Sheng et al., 1993
; Wang et al., 1993
; Scott et al., 1994a
), the
recent discovery and characterization of a family of
-subunits
(Rettig et al., 1994
; Scott et al., 1994b
; England et al., 1995a
,b
;
Heinemann et al., 1995
, 1996
; Majumder et al., 1995
; McCormack et al.,
1995
; Morales et al., 1995
; Rhodes et al., 1995
, 1996
; Fink et al.,
1996
; Nakahira et al., 1996
; Shi et al., 1996
) indicate that these
cytoplasmic polypeptides also make a significant contribution to
channel diversity. In particular, the Kv
1
-subunit has dramatic
effects on the inactivation of Shaker-related or Kv1
subfamily K+ channel
-subunits, although Kv
2
does not (Rettig et al., 1994
; Heinemann et al., 1996
). Moreover, it is
clear from these data that the association and localization of both
- and
-subunits must be considered to ascribe
electrophysiologically observed currents to channels of specific
subunit composition.
We described previously the expression and distribution of two
K+ channel
-subunits, Kv
1 (also referred to as
Kv
1a or Kv
1.1) and Kv
2, in rat brain (Rhodes et al., 1996
). We
also demonstrated that, in transfected cells, these
-subunits
associated with all Kv1
-subunits, but not with Kv2.1 (Nakahira et
al., 1996
).
- and
-Subunit interaction is mediated by domains in
the cytoplasmic N terminus of the
-subunit (Sewing et al., 1996
; Yu
et al., 1996
), near the domain responsible for mediating Kv1
subfamily-specific
-subunit oligomerization (for review, see
Scannevin and Trimmer, 1997
). In addition to the effects on
inactivation mediated by Kv
1, both Kv
1 and Kv
2 have been found
to exert chaperone-like effects on the surface expression of Kv1
subfamily
-subunits expressed in transfected cells (Shi et al.,
1996
), through an interaction occurring early in channel biosynthesis
(Shi et al., 1996
; Nagaya et al., 1997
).
The specific contribution of distinct
-subunit isoforms to
K+ channel complexes in mammalian brain and the
specific combinations of
- and
-subunit polypeptides that form
these complexes are important for correlating the channel subunits
identified in molecular cloning studies with neuronal
K+ currents. A combined biochemical and
neuroanatomical approach, as has been used to study the
-subunit
composition of hetero-oligomeric K+ channels in
mammalian brain (Sheng et al., 1993
; Wang et al., 1993
), is warranted
but requires the availability of subunit-specific antibodies to the
component
- and
-subunit polypeptides. Previously, we used a
pan-
-subunit antibody and antibodies against the Kv1.2, Kv1.4, and
Kv2.1
-subunits to begin to address the association and
colocalization of
- and
-subunit polypeptides in mammalian brain
(Rhodes et al., 1995
). We recently generated subtype-specific antibodies to Kv
1 and Kv
2 (Rhodes et al., 1996
) and a panel of
polyclonal and monoclonal antibodies to various K+
channel
-subunits (Bekele-Arcuri et al., 1996
; Shi et al., 1996
). Here we use these antibodies to immunopurify rat brain
K+ channel complexes and to determine the
constituent subunit composition by immunoblotting. We also use these
antibodies in single- and multiple-label immunohistochemical and
immunofluorescence analyses to examine the cellular and subcellular
colocalization of these channel polypeptides. Taken together, these
studies provide an important biochemical and neuroanatomical foundation
for increased understanding of the contribution of specific
K+ channel
- and
-subunits to multiple,
functionally distinct K+ currents in the brain.
MATERIALS AND METHODS
Materials. All reagents were molecular biology grade
from Sigma (St. Louis, MO) or Boehringer-Mannheim (Indianapolis, IN), except where noted otherwise.
Production of antibodies. The production of the anti-
-
and anti-
-subunit-specific monoclonal and affinity-purified
polyclonal antibodies is described in detail elsewhere (Trimmer, 1991
;
Rhodes et al., 1995
, 1996
; Bekele-Arcuri et al., 1996
; Shi et al.,
1996
). In brief, these antibodies were raised using synthetic peptides or fusion proteins as the immunogen. Each antibody was examined for
specificity on immunoblots of rat brain membranes, on immunoblots of
membranes prepared from COS-1 cells transiently transfected with a
broad panel of K+ channel cDNAs, and by
immunofluorescence staining of transiently transfected cells
(Bekele-Arcuri et al., 1996
). Each antibody recognized only the
appropriate protein on these immunoblots and stained only cells
transfected with the appropriate cDNA. Moreover, immunoreactivity was
completely eliminated by previous incubation with the corresponding
peptide or fusion protein immunogen.
Immunoprecipitation. A crude adult rat brain synaptosomal
membrane fraction was prepared as described previously (Trimmer, 1991
;
Rhodes et al., 1995
). Immunoprecipitation reactions were performed at
4°C using detergent lysates of these membranes as described
previously (Rhodes et al., 1995
, 1996
). In brief, membranes (1 mg of
membrane protein/tube) were solubilized to 1 ml final volume per tube
in lysis buffer [1% Triton X-100 and (in mM) 150 NaCl, 1 EDTA, 10 sodium azide, and 10 Tris-HCl, pH 8.0] containing a protease
inhibitor mixture (Trimmer, 1991
). Affinity-purified antibodies were
added, and the volume was adjusted to 1 ml with lysis buffer. Samples
were incubated for 2 hr on a rotator, followed by addition of 50 µl
of a 50% slurry of protein A-Sepharose and further incubation for 45 min. After incubation, protein A-Sepharose was pelleted by
centrifugation at 10,000 × g for 20 sec, and the resulting pellets were washed by resuspension and centrifugation six
times with lysis buffer. The final pellets were resuspended in 200 µl
of reducing SDS sample buffer.
SDS-polyacrylamide gels and immunoblotting. Products of
immunoprecipitation reactions (20 µl, representing the yield from 100 µg of starting crude rat brain membrane protein) were size fractionated on 9% (for analysis of
-subunit polypeptides) or 12%
(for analysis of
-subunit polypeptides) SDS-polyacrylamide gels
(Maizel, 1971
). Sixty micrograms of crude rat brain membrane protein
were also resuspended in reducing SDS sample buffer and loaded directly
onto each SDS gel. Disulfide bonds were reduced by the addition of 20 mM 2-mercaptoethanol to the sample buffer. Lauryl sulfate
(Sigma) was the SDS source used for all SDS-PAGE (Shi et al., 1994
).
After electrophoretic transfer to nitrocellulose paper, the resulting
blots were blocked in TBS containing 4% low-fat milk (Blotto) (Johnson
et al., 1984
), incubated in affinity-purified antibody diluted
1:50-1:2000 in Blotto for 1 hr or undiluted monoclonal antibody tissue
culture supernatants, and washed three times in Blotto for 30 min
total. Blots were then incubated in HRP-conjugated secondary antibody
(Organon Teknika, West Chester, PA; 1:2000 dilution in Blotto) for 1 hr
and then washed in TBS three times for 30 min total. The blots were
then incubated in substrate for enhanced chemiluminescence (ECL) for 1 min and autoradiographed on preflashed (to OD545 = 0.15)
Kodak (Rochester, NY) XAR-5 film.
Immunohistochemistry. The procedures for single-label light
microscopic immunohistochemistry are described in detail elsewhere (Rhodes et al., 1995
, 1996
; Bekele-Arcuri et al., 1996
). Briefly, 35-µm-thick sections of adult rat brain were incubated overnight at
4°C in an antibody vehicle containing affinity-purified rabbit polyclonal or mouse monoclonal antibodies. Detection of
antibody-antigen complexes was accomplished using the avidin-biotin
ABC procedure (Vector Laboratories, Burlingame, CA) and visualized
using a nickel-enhanced diaminobenzidine procedure (Rhodes et al.,
1995
, 1996
).
For multiple-label immunofluorescence, 10-µm-thick frozen sections
were mounted on glass slides and incubated for 36 hr at 4°C in an
antibody vehicle containing a mixture of affinity-purified rabbit
polyclonal and mouse monoclonal antibodies (Bekele-Arcuri et al.,
1996
). If two mouse monoclonal antibodies were used in the same
incubation, they were of distinct isotype. These sections were then
incubated in vehicle containing affinity-purified species- and
isotype-specific secondary antibodies conjugated to fluorescein (FITC),
Texas Red sulfonyl chloride (TRSC), or 7-amino-4-methylcoumarin 3-acetic acid (AMCA). Secondary antibodies conjugated to FITC were used
to label the most abundant (or most easily detected) antigen, and
antibodies conjugated to TRSC were used to label the least abundant (or
least easily detected) antigen. For triple labeling, sections were
incubated in antibody vehicle containing a mixture of two
isotype-specific mouse monoclonal antibodies plus a rabbit polyclonal
antibody. The sections were then incubated in antibody vehicle
containing fluorochrome-conjugated, isotype-specific secondary
antibodies (Southern Biotechnology, Inc., Atlanta, GA; or
Boehringer-Mannheim, Indianapolis, IN), plus an affinity-purified, fluorochrome-conjugated anti-rabbit secondary antibody. For example, for triple labeling of Kv1.1, Kv1.2, and Kv
2, we used the
affinity-purified rabbit anti-Kv1.1 antibody, the mouse K14/16 (IgG2b)
anti-Kv1.2 monoclonal antibody, and the mouse K17/70 (IgG1) anti-Kv
2
monoclonal antibody (Bekele-Arcuri et al., 1996
; Shi et al., 1996
) to
detect the corresponding antigens. We then used an affinity-purified, AMCA-conjugated goat anti-rabbit secondary antibody to label Kv1.1, an
FITC-conjugated goat anti-mouse-IgG2b secondary antibody to label
Kv1.2, and a TRSC-conjugated goat anti-mouse-IgG1 secondary antibody to
label Kv
2. The sections were then washed in PBS, dried, and
coverslipped using ProLong mounting medium (Molecular Probes, Eugene,
OR).
Sections processed for immunofluorescence were viewed and analyzed
using a computer-based image analysis system (Micro Computer Imaging
Device M2; Imaging Research) coupled to a Zeiss Axiovert microscope
equipped with epifluorescence illumination as well as appropriate
excitation, bandpass, and barrier filter sets (Omega Optical,
Brattleboro, VT). This system was equipped with a Sony DXC-97 OMD color
CCD camera that, under computer control, was capable of integrating
fluorescent signals over a user-defined time interval. This system was
also equipped with color imaging hardware that permitted us to view and
digitize true color images of immunofluorescent specimens. In some
cases in which triple-label immunofluorescence was performed, digitized
color images of the three individual fluorochromes were combined
("image fusion") to generate a single composite image in which the
extent of immunofluorescent colocalization could be determined
directly. Images obtained using this digital imaging approach were
printed directly from the imaging system using a Fuji Pictrographic
color printer.
To determine the specificity of the immunohistochemical reactions, some
sections were processed either without addition of the primary antibody
or using antibodies previously incubated (1 hr) in vehicle containing
an excess of the corresponding immunogen (5-25 µg/ml) (Rhodes et
al., 1995
, 1996
; Bekele-Arcuri et al., 1996
). Additionally, some
sections processed using mouse monoclonal primary antibodies were
reacted with fluorochrome-tagged goat anti-rabbit secondary antibodies
and vice versa. Finally, each of the isotype-specific anti-mouse
secondary antibodies was tested versus primary antibodies of
nonmatching isotype and versus the rabbit polyclonal antibodies. We did
not observe any specific staining with the primary antibodies after
exposure to the appropriate immunogen, nor did we observe cross-species
or cross-isotype reactivity of fluorochrome-tagged secondary
antibodies. We also did not observe any bleed-through detection of
fluorochrome-tagged secondary antibodies using filter sets for the
other fluorochromes.
RESULTS
Reciprocal coimmunoprecipitation analyses reveal association of
Kv
1 and Kv
2 with Kv1 subfamily
-subunits in mammalian
brain
To determine the association of Kv
1 and Kv
2 with specific
-subunits in rat brain K+ channel complexes, we
performed reciprocal coimmunoprecipitation experiments using anti-
-
and anti-
-subunit-specific antibodies. Detergent lysates were
prepared from rat brain membranes under conditions previously shown to
preserve
- and
-subunit interactions (Rhodes et al., 1995
, 1996
;
Nakahira et al., 1996
; Shi et al., 1996
). These lysates were then used
in immunoprecipitation reactions performed with the anti-Kv
1 and
anti-Kv
2 polyclonal antibodies (Rhodes et al., 1996
) and with
isotype-specific antibodies against the Kv1.1, Kv1.2, Kv1.4, Kv1.6, and
Kv2.1
-subunits (Trimmer, 1991
; Rhodes et al., 1995
, 1996
;
Bekele-Arcuri et al., 1996
; Nakahira et al., 1996
; Shi et al., 1996
).
In each case, immunoprecipitation reactions were performed under
conditions of antibody excess, which was verified by subsequent removal
and analysis of the depleted supernatant after pelleting of the
immunoprecipitation reaction product. In each case all recoverable
antigen had been removed by the initial immunoprecipitation reaction.
Immunoprecipitation products, representing immunopurified channel
complexes, were then subjected to immunoblot analyses to assay for the
presence of the specific
- and
-subunit polypeptides.
Immunoprecipitation reactions were first analyzed for the presence of
the Kv
1
-subunit polypeptide using an affinity-purified rabbit
polyclonal antibody raised against the unique N-terminus of the Kv
1
polypeptide (Rhodes et al., 1996
). In coexpression studies, recombinant
Kv
1 has been shown to confer rapid inactivation on all members of
the Kv1 subfamily
-subunits tested, with the exception of Kv1.6,
suggesting that this
-subunit could be an important modulator of
K+ channel complexes containing Kv1
-subunits
(Rettig et al., 1994
; Heinemann et al., 1996
). As expected from our
previous studies (Rhodes et al., 1996
), anti-Kv
2 antibodies
quantitatively coimmunoprecipitated the 44 kDa Kv
1 polypeptide from
these rat brain extracts (Fig. 1,
top panel), showing that most of the channel
complexes that contain Kv
1 also contain at least one Kv
2
-subunit. In addition, all of the Kv1 family members tested (Kv1.1,
Kv1.2, Kv1.4, and Kv1.6) were able to coimmunoprecipitate Kv
1,
indicating that a portion of the total pool of each Kv1
-subunit in
the brain is present in complexes that contain Kv
1. Of these, the
immunoprecipitation reaction performed with the anti-Kv1.1 antibody
contained the most Kv
1, followed by the Kv1.2, Kv1.4, and Kv1.6.
Antibodies to Kv2.1 did not coimmunoprecipitate any detectable
Kv
1, extending previous results obtained using a pan-
-subunit
antibody in rat brain (Rhodes et al., 1995
), and on recombinant
K+ channel subunits expressed in transfected cells
(Nakahira et al., 1996
), which suggested a lack of interaction between
Kv
1 and Kv2.1.
Fig. 1.
Presence of Kv
1 and Kv
2 in rat brain
K+ channel complexes. A detergent lysate of adult
rat brain membranes (RBM; 60 µg) and aliquots of
products of immunoprecipitation reactions from detergent extracts of
100 µg of RBM performed with the indicated rabbit polyclonal
antibodies were size-fractionated by 12% SDS-PAGE. Samples were
transferred to nitrocellulose and probed with affinity-purified rabbit
anti-Kv
1 polyclonal antibody (top panel) or
mouse anti-Kv
2 monoclonal antibody K17/70 (bottom
panel). Bound antibody was detected by ECL and
autoradiography for 15 min (top panel) or 5 min
(bottom panel). Arrows on the
top panel point to the band resulting from detection of
the rabbit IgG used in the immunoprecipitation reactions by the
anti-rabbit secondary antibody used for immunoblotting (IgG) and the Kv
1-specific band
(Kv
1). Rabbit IgG bands are not
present in the bottom panel, because the immunoblot was
developed with anti-mouse secondary antibodies.
Kv
2 arrow denotes the Kv
2
-subunit. Numbers at the left denote
Mr values of prestained molecular weight
standards.
[View Larger Version of this Image (48K GIF file)]
A similar approach was used to characterize
- and
-subunit
polypeptides that associate with Kv
2, using the Kv
2-specific monoclonal antibody K17/70 (Bekele-Arcuri et al., 1996
) to probe immunopurified K+ channel complexes (Fig. 1,
bottom panel). The Kv
2 subunit pool in rat brain
consists of two components of Mr = 38 and 41 kDa. The molecular basis of the size differences between these two polypeptide species that share immunoreactivity with both N-terminally directed Kv
2-specific monoclonal and polyclonal antibodies (Rhodes et al., 1996
) and C-terminally directed pan-
-subunit monoclonal and
polyclonal antibodies (Rhodes et al., 1995
) is not known. Immunoprecipitation reactions performed with the anti-Kv
1 antibody yielded only small amounts of Kv
2, consistent with previous studies (Rhodes et al., 1996
) that suggested that Kv
1 is a minor brain
-subunit relative to Kv
2, and that very few of the
Kv
2-containing K+ channel complexes in the brain
contain Kv
1. All of the Kv1 family members tested were found to
exist in complexes containing Kv
2, with anti-Kv1.1 and anti-Kv1.2
antibodies the most effective at coimmunoprecipitating Kv
2 and
anti-Kv1.4 and anti-Kv1.6 antibodies less effective (Fig. 1,
bottom panel). Kv
2, like Kv
1, could not be
coprecipitated by antibodies to Kv2.1. It should be noted that each of
the anti-
-subunit and anti-Kv1 subfamily
-subunit antibodies
tested could coimmunoprecipitate both the 38 and 41 kDa components of
the rat brain Kv
2 pool, although the 41 kDa band is not visible in
all samples on the exposure presented here (Fig. 1, bottom
panel).
Reciprocal immunoblots were performed using antibodies specific for
each of the
-subunit polypeptides. Each of the affinity-purified rabbit polyclonal anti-
-subunit antibodies could directly
immunoprecipitate the respective
-subunit from the brain membrane
extracts (Fig. 2). Immunoprecipitation
reactions performed with the anti-Kv
2 antibody were quite effective
at coimmunoprecipitating the bulk of the Kv1.1, Kv1.2, Kv1.4, and Kv1.6
-subunits, indicating that the bulk of the K+
channel complexes in the brain that contain these
-subunits also
contain Kv
2. Kv1.1 and Kv1.4 and, to a lesser extent, Kv1.2 and
Kv1.6 could be detected in K+ channel complexes
immunopurified using the anti-Kv
1 antibody (Fig. 2). However, the
amount of these Kv1 subfamily
-subunits that were found associated
in complexes containing Kv
1 was substantially less than those found
with Kv
2, consistent with the overall lower levels of Kv
1 present
in the brain. Neither the anti-Kv
1 nor anti-Kv
2 antibody could
coimmunoprecipitate the Kv2.1
-subunit, even though the
Kv2.1-specific antibody could efficiently directly precipitate this
-subunit (Fig. 2). Overall, these results suggest that the vast
majority of Kv1-containing K+ channel complexes in
the brain contain at least one Kv
2
-subunit, and that complexes
containing Kv
1 are also present but are far less abundant.
Fig. 2.
Presence of
-subunits in rat brain
K+ channel complexes. A detergent lysate of adult
rat brain membranes (RBM; 60 µg) and aliquots of
products of immunoprecipitation reactions from detergent extracts of
100 µg of RBM performed with polyclonal antibodies specific for the
indicated K+ channel
- and
-subunit
polypeptides were size-fractionated by 9% SDS-PAGE. Samples were
transferred to nitrocellulose and then probed with subunit-specific
affinity-purified rabbit antibodies. The panels represent blots probed
with the following antibodies and the respective exposure times for ECL
and autoradiography: Kv1.1 (top left; 40 sec), Kv1.2
(top right; 5 min), Kv1.4 (middle left; 2 min) Kv1.6 (middle right; 40 sec), and Kv2.1
(bottom, 20 min). Bound antibody was detected by ECL and
autoradiography. Arrows point to the respective
-subunit polypeptides; also visible are bands resulting from
detection of the rabbit IgG used in the immunoprecipitation reactions
by the anti-rabbit secondary antibody used for immunoblotting.
Numbers at the left denote
Mr values of prestained molecular weight
standards.
[View Larger Version of this Image (50K GIF file)]
Immunohistochemical colocalization of
- and
-subunit polypeptides
To examine the distribution and colocalization of Kv
1 and
Kv
2 with
-subunits of the Kv1 and Kv2 subfamilies, these same antibodies were used in immunohistochemical studies in serial sections
of rat brain. Using these sections, we made side-by-side comparisons of
the immunohistochemical staining pattern and subcellular distribution
of each subunit. But because we cannot conclude from comparisons in
adjacent sections that individual subunits are precisely colocalized,
here we use the term "codistributed" to refer to instances in which
subunits are found in identical cell types and subcellular domains, but
in adjacent sections. In some cases, the colocalization of
- and
-subunits was examined directly using dual- or triple-label
immunofluorescence in a single tissue section. When these direct,
within-section comparisons were made, we use the term "colocalized"
to refer to the precise superimposition of fluorochromes identifying
two or more distinct subunits. With these distinctions in mind, the
salient features of the immunohistochemical staining are described
below with emphasis on three areas: the hippocampal formation, the
globus pallidus, and the cerebellar cortex.
Hippocampal formation
Low-magnification photomicrographs showing the distribution of
immunoreactivity for Kv1.1, Kv1.2, Kv1.4, Kv1.6, Kv
1, Kv
2, and
Kv2.1 in the hippocampus are shown in Figure
3. In the dentate gyrus, there is a close
correspondence between the distribution of Kv
1 and Kv
2 and the
Kv1.1, Kv1.2, and Kv1.4
-subunits. All five of these subunits are
concentrated in a prominent band located in the middle third of the
molecular layer. Sections taken through the dentate gyrus processed for
triple-label immunofluorescence clearly demonstrate the colocalization
of Kv1.1, Kv1.4, and Kv
1 in the middle third of the molecular layer
(Fig. 4). As described previously by us
and by others (Sheng et al., 1993
; Wang et al., 1993
, 1994
; Rhodes et
al., 1995
), this pattern closely matches the termination zone of the
medial perforant path (see Rosene and Van Hoesen, 1987
) and correlates
well with the high density of Kv
1 and Kv
2, as well as Kv1.1,
Kv1.2, and Kv1.4, mRNA expression in cells located in layer II of the
entorhinal cortex (Sheng et al., 1994
; Wang et al., 1994
; Rhodes et
al., 1996
) (N. X. Barrezueta, M. M. Monaghan, J. S. Trimmer, and K. J. Rhodes, unpublished observations), suggesting
that all five subunits are localized at or near the axon terminals of
entorhinal afferents. In inner and outer thirds of the molecular layer
of the dentate gyrus, there is also diffuse immunoreactivity for Kv1.2,
Kv1.4, Kv1.6, Kv
1, and Kv
2. This staining may represent subunit
expression in the dendrites of dentate granule cells (see Wang et al.,
1994
) or in axons of other afferent inputs to the dentate gyrus, e.g.,
the dentate gyrus association pathway and basal forebrain cholinergic
system.
Fig. 3.
Immunohistochemical localization of
K+ channel
- and
-subunits in rat hippocampus.
Arrows in B-D, F, and G
point to the band of immunoreactivity for Kv1.1, Kv1.2, Kv1.4, Kv
1,
and Kv
2, respectively, in the middle third of the molecular layer of
the dentate gyrus (DG). Arrowheads mark
the boundaries between hippocampal subfields.
[View Larger Version of this Image (145K GIF file)]
Fig. 4.
Triple-label immunfluorescence demonstrating the
colocalization of Kv1.1 (A), Kv1.4
(B), and Kv
1 (C) in the
dentate gyrus. These three subunits are colocalized in the middle third
of the molecular layer, in a pattern that overlaps with terminals of the medial perforant path. gc, Granule cell layer;
it, inner third of the molecular layer;
mt middle third of the molecular layer; ot, outer third of the molecular layer.
[View Larger Version of this Image (118K GIF file)]
In the CA3 subfield, there is a prominent band of immunoreactivity for
Kv
1, Kv1.1, and Kv1.4 in a narrow zone immediately above stratum
pyramidale of CA3 (Figs. 3, 5). The
location of this band suggests that these three subunits are associated
with mossy fiber axons (also see Wang et al., 1994
). Surprisingly, there was not a clear band of immunoreactivity for Kv1.2 or Kv
2 in
the mossy fiber termination zone, indicating that Kv1.2 and Kv
2 are
either not present in these K+ channel complexes or
are not detectable by our antibodies. Many medium- to large-sized
interneurons located within stratum pyramidale, stratum oriens, and
stratum radiatum of CA1-CA3 and in the subiculum were strongly
immunoreactive for Kv
1 and were also immunoreactive for Kv1.1 and
Kv1.6. A subpopulation of interneurons located within and immediately
adjacent to stratum pyramidale were also immunoreactive for Kv1.4 and
Kv
2, suggesting that these cells may express K+
channel complexes containing four different Kv1
-subunits in addition to both
-subunits. As mentioned above, the coexpression of
Kv
1 with Kv1.1 and Kv1.4 within these cells suggests that they most
likely contain a high density of rapidly inactivating, dendrotoxin
(DTX)-sensitive channels.
Fig. 5.
Triple-label immunfluorescence demonstrating the
colocalization of KvB1 (A), Kv1.1
(B), and Kv1.4 (C) in the
mossy fiber zone of CA3. These three subunits are colocalized at or
near the terminals of the mossy fiber pathway. py,
Stratum pyramidale; mf, mossy fiber zone.
[View Larger Version of this Image (135K GIF file)]
In stratum radiatum and stratum oriens of CA1-CA3 there is a
prominent zone of immunoreactivity for Kv1.1 that corresponds precisely
with the termination zone of the Schaffer collateral pathway (Fig. 3).
This zone of Kv1.1 immunoreactivity is matched by similar, although
much less prominent, patterns of immunoreactivity for Kv1.4, Kv
1,
and Kv
2. In stratum moleculare of CA1-CA3 there is a band of
immunoreactivity for Kv1.2 and Kv1.4 and a weaker, less distinct band
of immunoreactivity for Kv
2 (Fig. 3). Interestingly, the location of
this band corresponds precisely to the termination zone of the
perforant path. Somewhat surprisingly, this CA component of the
perforant path seems to lack Kv1.1, suggesting that the subunit
composition of channel complexes located on the Ammonic and dentate
components of the perforant path are distinct. Moreover, the inclusion
of Kv1.2 in these complexes, together with Kv1.4, would be expected to
confer DTX sensitivity to these channels.
As described previously (Rhodes et al., 1995
; Bekele-Arcuri et al.,
1996
), Kv2.1 immunoreactivity is present in many of the same neurons
that are immunoreactive for Kv1
- and
-subunits. However, in
these cells, immunoreactivity for Kv2.1 is concentrated in large
patches on the somatodendritic membrane (see Scannevin et al., 1996
),
whereas immunoreactivity for the Kv1
- and
-subunits is
concentrated in axons and terminal fields or is distributed evenly
throughout the cell soma and along dendritic processes. These
differences between the qualitative appearance of Kv2.1 immunoreactivity from that observed for the other subunits are consistent with our biochemical data and indicate that Kv2.1 does not
associate with these subunits despite extensive cellular
coexpression.
Caudate nucleus, globus pallidus, and substantia nigra
Moderate to high levels of Kv1.1, Kv1.4, Kv
1, and Kv
2 mRNA
expression have been observed in rat caudate nucleus (Sheng et al.,
1992; Rettig et al., 1994
; Wang et al., 1994
; Rhodes et al., 1996
),
with low levels in the globus pallidus and substantia nigra. However,
only moderate to low levels of immunoreactivity for these subunits have
been observed in the caudate nucleus itself, suggesting that the
corresponding polypeptides are likely to be concentrated at or near the
axons and terminals of striatal neurons. In fact, there is a moderate
to high density of immunoreactivity for Kv1.1, Kv1.4, Kv
1, and
Kv
2 in both of the major subcortical targets of striatal efferents,
the globus pallidus and the pars reticulata of the substantia nigra
(Fig. 6). The pattern of immunoreactivity in these latter structures indicates that Kv1.1, Kv1.4, Kv
1, and
Kv
2 are codistributed at or near the terminal fields of striatal efferents where they may regulate GABAergic or peptidergic (substance P
and enkephalin) neurotransmission.
Fig. 6.
Immunohistochemical localization of Kv1.1, Kv1.4,
Kv
1, and Kv
2 (A-D, respectively) in the caudate
nucleus (CPu), globus pallidus (GP;
arrowheads), and pars reticulata of the substantia nigra
(SNr). These four subunits are codistributed in the
termination zones of neostriatal efferents to the globus pallidus and
substantia nigra.
[View Larger Version of this Image (179K GIF file)]
Cerebellar cortex
As described previously by us (Rhodes et al., 1995
, 1996
) and by
others (McNamara et al., 1993
, 1996
; Sheng et al., 1993
; Wang et al.,
1993
, 1994
; Scott et al., 1994a
; Veh et al., 1995
), there is a high
density of Kv1.1, Kv1.2, Kv
1, and Kv
2, and a much lower density
of Kv1.4 and Kv1.6 in the cerebellum (Fig. 7). Perhaps the greatest concentration of
Kv1.1, Kv1.2, and Kv
2 in the entire brain is found in the axon
terminal plexuses of cerebellar granule cells that surround the initial
segment of Purkinje cell axons. When these three subunits are
visualized simultaneously in a single tissue section by triple-label
immunofluorescence (Fig. 8), it is
apparent that these subunits are precisely colocalized in this terminal
plexus. Similarly, it is obvious that these three subunits are
precisely colocalized in the juxtaparanodal region of virtually all
myelinated axons located in the cerebellar white matter (Fig.
9). Because neither Kv
1 nor Kv1.4 is
expressed at either the basket cell terminals or at nodes of Ranvier in
the cerebellar white matter, Kv1.1, Kv1.2, and Kv
2 associate here to
form what is likely a DTX-sensitive, slowly inactivating, delayed rectifier type channel complex. Interestingly, immunoreactivity for
Kv1.1 is also concentrated in the neuropil of the molecular layer of
the cerebellar cortex. This pattern of Kv1.1 immunoreactivity is
matched by much weaker immunoreactivity for Kv1,4, Kv1.6, Kv
1, and
Kv
2, suggesting that these subunits may all be localized on afferent
inputs to the cerebellar cortex.
Fig. 7.
Immunohistochemical localization of
K+ channel
- and
-subunits in the cerebellar
cortex. Note the high density of immunoreactivity for Kv1.1, Kv1.2, and
Kv
2 in the terminals of cerebellar basket cells
(arrows).
[View Larger Version of this Image (179K GIF file)]
Fig. 8.
Triple-label immunfluorescence demonstrating the
colocalization of Kv1.1 (A), Kv1.2
(B), and Kv
2 (C) in
cerebellar basket cell terminals. Arrows point to the
terminal Pinceau of cerebellar basket cells, where all three subunits
are colocalized.
[View Larger Version of this Image (107K GIF file)]
Fig. 9.
Triple-label immunfluorescence demonstrating the
colocalization of Kv1.1 (A), Kv1.2
(B), and Kv
2 (C) at the
juxtaparanodal region of nodes of Ranvier in the cerebellar white
matter. Arrows point to the juxtaparanodal membrane of a
node of Ranvier.
[View Larger Version of this Image (107K GIF file)]
DISCUSSION
The results of the present study indicate that Kv
1 and Kv
2
associate and colocalize with each other and with each of the Shaker-related Kv1
-subunits but not with the
Shab-related Kv2.1
-subunit. These data confirm and
extend our previous studies performed with a pan-
-subunit antibody
that recognizes both Kv
1 and Kv
2, which showed
-subunit
association and colocalization with Kv1.2 and Kv1.4 but not Kv2.1
(Rhodes et al., 1995
). These results are also consistent with our
previous studies of recombinant
- and
-subunit polypeptides
expressed in transfected cells, in which both Kv
1 and Kv
2 were
found to associate with all members of the Kv1 subfamily tested but not
with Kv2.1 (Nakahira et al., 1996
).
Although Kv
1 and Kv
2 are found associated with all of the Kv1
subfamily members examined, distinct differences in the levels of
specific
-subunit polypeptides that could be coimmunoprecipitated with the different
-subunit-specific antibodies were observed. For
example, most if not all of the Kv1.1, Kv1.2, Kv1.4, and Kv1.6 in these
brain preparations was present in complexes containing at least one
Kv
2
-subunit, based on the amount of the
-subunit coimmunoprecipitated by the Kv
2 antibody relative to that obtained by direct immunoprecipitation with the respective
-subunit-specific antibody. In contrast, only small fractions of the pool of rat brain
Kv1.1 and Kv1.4, and even less of Kv1.2 and Kv1.6, were found in
K+ channel complexes immunopurified with the
anti-Kv
1 antibody. These data together predict that overall in the
brain, most if not all Kv1-containing K+ channel
complexes contain Kv
2, whereas few have Kv
1 as a constituent subunit. These results are especially intriguing given that
Kv1-containing K+ channel complexes are thought to
have an
4
4 subunit composition (Parcej et
al., 1992
). Thus, despite the presence of four
-subunits per
K+ channel complex, only a small proportion of rat
brain K+ channels have even a single Kv
1 subunit
present. These results are consistent with our previous studies that
indicated that Kv
2 was overall much more abundant than Kv
1 in the
brain, and that most
-subunit-containing K+
channel complexes contain Kv
2 in the absence of Kv
1 (Rhodes et
al., 1996
). However, it is important to stress that these data reflect
only the overall bulk of all brain Kv1-containing channel complexes and
in no way preclude the possibility that important pools of
channels in discrete neuronal populations may be under the functional
influence of the inactivation-modulating Kv
1 subunit.
Our immunoprecipitation data show that all of the Kv1 family members
tested could be found in association with Kv
1 and Kv
2 and vice
versa. Recently, members of the mammalian disks large family, such as
postsynaptic density protein (PSD)-95 and synapse associated protein
(SAP)-97, have been shown to interact with Kv1 family members and to
induce their clustering through the formation of large, multiprotein
complexes (Kim et al., 1995
; Sheng and Kim, 1996
). It is formally
possible that such interactions between multiple
Kv1-containing K+ channel complexes could complicate
studies of subunit associations within K+
channel complexes. However, immunoblot analyses using antibodies that
recognize PSD-95 and SAP-97 could not detect these proteins in any of
the anti-
- or anti-
-subunit immunoprecipitation reactions characterized here (Z. Bekele-Arcuri and J. S. Trimmer,
unpublished observations). These results suggest that if such
supramolecular aggregation of K+ channel
- and
-subunit polypeptides does occur, it apparently does not remain
intact under the detergent extraction conditions used here that are
designed to maintain subunit interactions within K+
channel complexes.
Direct comparisons of the cellular localization of Kv
1 and Kv
2
immunoreactivity with staining for the Kv1.1, Kv1.2, Kv1.4, Kv1.6, and
Kv2.1
-subunits in sequential sections confirmed the immunoprecipitation data and indicated that there is extensive overlap
in the distribution of Kv
1 with Kv1.1 and Kv1.4 and extensive overlap in the distribution of Kv
2 with Kv1.1 and Kv1.2. In
addition, triple immunofluorescence labeling of Kv1.1, Kv1.2, and
Kv
2 indicated that these three subunits are precisely colocalized in
many brain regions and strikingly so in the juxtaparanodal membrane at
nodes of Ranvier and in the terminals of cerebellar basket cells.
Triple-label immunofluorescence also revealed that in the hippocampal
mossy fiber pathway (Fig. 5) and in the globus pallidus (data not
shown), Kv1.1, Kv1.4, and Kv
1 are precisely colocalized. Together,
the immunoprecipitation and immunohistochemical data indicate that although Kv
1 is widely expressed in the brain, this
-subunit seems to be preferentially expressed in cell types and projection systems that also express a high density of Kv1.1 and Kv1.4. The tendency of Kv
1 to associate and colocalize with Kv1.1 and Kv1.4 in
the brain is intriguing, because Kv
1 has been shown to dramatically accelerate the kinetics of inactivation of Kv1.1 and Kv1.4 and other
Kv1 subfamily members on transient coexpression in Xenopus oocytes (Rettig et al., 1994
; Heinemann et al., 1996
). Thus it appears
that Kv
1 may be incorporated into native K+
channel complexes that produce DTX-sensitive transient
K+ currents. This conclusion is based on a number of
considerations. First, when the DTX-sensitive, noninactivating Kv1.1
-subunit is coexpressed with the DTX-insensitive, rapidly
inactivating Kv1.4
-subunit, DTX-sensitive, rapidly inactivating
currents indicative of the heteromultimeric channels are obtained
(Ruppersberg et al., 1990
). Second, coexpression of Kv
1 confers
rapid inactivation on the normally noninactivating Kv1.1 currents and
in fact further accelerates the inactivation of Kv1.4 (Rettig et al.,
1994
; Heinemann et al., 1996
). Thus, channels containing Kv1.1, Kv1.4,
and Kv
1 would be expected to have rapid inactivation typical of
transient or IA currents and to exhibit sensitivity to
block by DTX. This may explain the initial discrepancy that cloned
cDNAs that yield transient currents (Kv1.4, Kv4.2, and Kv4.3)
in each case are DTX-insensitive, yet many of the
IA currents that have been recorded from central
neurons are DTX-sensitive (Halliwell, 1990
; Harvey, 1997
).
Using a similar logic, channels composed of Kv1.1, Kv1.2, and Kv
2, such as those seen in juxtaparanodal regions and in basket cell
terminals would be predicted to form DTX-sensitive, noninactivating, delayed rectifier channels, giving rise to
IK(DTX) currents similar to those that have been
described in peripheral neurons (Stansfeld and Feltz, 1988
; Safronov et
al., 1993
). These DTX-sensitive, noninactivating and slowly
inactivating currents at peripheral nodes of Ranvier have been studied
extensively; however, such currents in central neurons are less well
characterized, perhaps attributable to their inaccessibility at nodes
and at presynaptic terminals. Thus the specific contribution of these
abundant Kv1.1, Kv1.2, and Kv
2 channel complexes to neuronal
K+ currents in the cerebellum and in other regions
rich in this channel type remains unclear.
Since the initial cloning of Kv
1 and Kv
2 from mammalian brain
(Rettig et al., 1994
; Scott et al., 1994b
), other
-subunit cDNAs
have also been isolated. An alternative splice variant of Kv
1,
termed Kv
1b or Kv
1.2, has been isolated from human, ferret, and
rat heart (England et al., 1995a
,b
; Majumder et al., 1995
; Morales et
al., 1995
). Effects of this
-subunit on Kv subunits appear to be
restricted to Kv1.4 and Kv1.5, with no observed effects on Kv1.1,
Kv1.2, and Kv2.1. The expression pattern of Kv
1b in the brain is not
known. As mentioned above, a cDNA arising from a third
-subunit
gene, Kv
3, has also been isolated from rat brain (Heinemann et al.,
1995
). Effects of this
-subunit are restricted to accelerating the
inactivation of the transient Kv1.4 current further; effects on other
Kv1 subfamily members were not observed (Heinemann et al., 1995
). A
-subunit, Kv
4, that enhances expression of rat Kv2.2, but has no
effects on any of the Kv1 subfamily members tested, has also been
recently identified (Fink et al., 1996
). Additional studies will be
required to determine the subunit associations of these recently
identified
-subunits, and others that may arise from alternative
splicing of the highly complex Kv
1 gene (Leicher et al., 1996
), to
determine their relative contributions to voltage-gated
K+ currents in the mammalian CNS.
FOOTNOTES
Received June 16, 1997; revised Aug. 13, 1997; accepted Aug. 18, 1997.
This work was supported by Wyeth-Ayerst Research (Princeton, NJ) and by
National Institutes of Health Grant NS34383 (J.S.T.). This work was
done during the tenure of an Established Investigatorship from the
American Heart Association (J.S.T.). We thank Drs. John A. Moyer and
James E. Barrett for critically reviewing this manuscript.
Correspondence should be addressed to Dr. James S. Trimmer, Department
of Biochemistry and Cell Biology, State University of New York, Stony
Brook, NY 11794-5215.
REFERENCES
-
Bekele-Arcuri Z,
Matos MF,
Manganas L,
Strassle BW,
Monaghan MM,
Rhodes KJ,
Trimmer JS
(1996)
Generation and characterization of subtype-specific monoclonal antibodies to K+ channel
- and
-subunit polypeptides.
Neuropharmacology
35:851-865[Web of Science][Medline]. -
England SK,
Uebele VN,
Kodali J,
Bennett PB,
Tamkun MM
(1995a)
A novel K+ channel
-subunit (hKv
1.3) is produced via alternative mRNA splicing.
J Biol Chem
270:28531-28534[Abstract/Free Full Text]. -
England SK,
Uebele VN,
Shear H,
Kodali J,
Bennett PB,
Tamkun MM
(1995b)
Characterization of a voltage-gated K+ channel
subunit expressed in human heart.
Proc Natl Acad Sci USA
92:6309-6313[Abstract/Free Full Text]. -
Fink M,
Duprat F,
Lesage F,
Heurteaux C,
Romey G,
Barhanin J,
Lazdunski M
(1996)
A new K+ channel
subunit to specifically enhance Kv2.2 (CDRK) expression.
J Biol Chem
271:26341-26348[Abstract/Free Full Text]. -
Halliwell JV
(1990)
K+ channels in the central nervous system.
In: Potassium channels (Cook NS,
ed), pp 350-359. New York: Wiley.
-
Harvey AL
(1997)
Recent studies on dendrotoxins and potassium ion channels.
Gen Pharmacol
28:7-12[Web of Science][Medline].
-
Heinemann SH,
Rettig J,
Wunder F,
Pongs O
(1995)
Molecular and functional characterization of a rat brain Kv
3 potassium channel subunit.
FEBS Lett
377:383-389[Web of Science][Medline]. -
Heinemann SH,
Rettig J,
Graack HR,
Pongs O
(1996)
Functional characterization of K-v channel beta-subunits from rat brain.
J Physiol (Lond)
493:625-633[Abstract/Free Full Text].
-
Hille B
(1992)
In: Ionic channels of excitable membranes. Sunderland, MA: Sinauer.
-
Jan LY,
Jan YN
(1997)
Cloned potassium channels from eukaryotes and prokaryotes.
Annu Rev Neurosci
20:91-123[Web of Science][Medline].
-
Johnson DAG,
Sportsman JR,
Elder JH
(1984)
Improved technique utilizing nonfat dry milk for analysis of proteins and nucleic acids transferred to nitrocellulose.
Gene Anal Tech
1:3-8.
-
Kim E,
Neithammer M,
Rothschild A,
Jan YN,
Sheng M
(1995)
Clustering of shaker-type K+ channels by interaction with a family of membrane-associated guanylate kinases.
Nature
387:85-88.
-
Leicher T,
Roeper J,
Weber K,
Wang X,
Pongs O
(1996)
Structural and functional characterization of human potassium channel subunit Kv
1 (KCNA1B).
Neuropharmacology
35:787-796[Web of Science][Medline]. -
Maizel JV
(1971)
Polyacrylamide gel electrophoresis of viral proteins.
Methods Virol
5:179-246.
-
Majumder K,
De Biasi M,
Wang Z,
Wible BA
(1995)
Molecular cloning and functional expression of a novel potassium channel
-subunit from human atrium.
FEBS Lett
361:13-16[Web of Science][Medline]. -
McCormack K,
McCormack T,
Tanouye M,
Rudy B,
Stümer W
(1995)
Alternative splicing of the human Shaker K+ channel
1 gene and functional expression of a
2 gene product.
FEBS Lett
370:32-36[Web of Science][Medline]. -
McNamara NM,
Muniz ZM,
Wilkin GP,
Dolly JO
(1993)
Prominent location of a K+ channel containing the
subunit Kv1.2 in the basket cell nerve terminals of rat cerebellum.
Neuroscience
57:1039-1045[Web of Science][Medline]. -
McNamara NMC,
Averill S,
Wilkin GP,
Dolly JO,
Priestly JV
(1996)
Ultrastructural localization of a voltage-gated K+ channel
subunit (Kv1.2) in the rat cerebellum.
Eur J Neurosci
8:688-699[Web of Science][Medline]. -
Morales MJ,
Castellino RC,
Crews AL,
Rasmussen RL,
Strauss HC
(1995)
A novel
subunit increases the rate of inactivation of specific voltage-gated potassium channel
subunits.
J Biol Chem
270:6272-6277[Abstract/Free Full Text]. -
Nagaya N,
Papazian DM
(1997)
Potassium channel
- and
-subunits assemble in the endoplasmic reticulum.
J Biol Chem
272:3022-3027[Abstract/Free Full Text]. -
Nakahira K,
Shi G,
Rhodes KJ,
Trimmer JS
(1996)
Selective interaction of voltage-gated K+ channel
-subunits with
-subunits.
J Biol Chem
271:7084-7089[Abstract/Free Full Text]. -
Parcej DN,
Scott VES,
Dolly JO
(1992)
Oligomeric properties of
-dendrotoxin-sensitive potassium ion channels purified from bovine brain.
Biochemistry
31:11084-11088[Medline]. -
Pongs O
(1995)
Regulation of the activity of voltage-gated potassium channels by
subunits.
Semin Neurosci
7:137-146. -
Rettig J,
Heinemann SH,
Wunder F,
Lorra C,
Parcej DN,
Dolly JO,
Pongs O
(1994)
Inactivation properties of voltage-gated K+ channels altered by presence of
-subunit.
Nature
369:289-294[Medline]. -
Rhodes KJ,
Keilbaugh SA,
Barrezueta NX,
Lopez KL,
Trimmer JS
(1995)
Association and colocalization of K+ channel
- and
-subunit polypeptides in rat brain.
J Neurosci
15:5630-5671. -
Rhodes KJ,
Monaghan MM,
Bekele-Arcuri Z,
Matos MF,
Trimmer JS
(1996)
Voltage-gated K+ channel
-subunit polypeptides: expression and distribution of Kv
1 and Kv
2 in adult rat brain.
J Neurosci
16:4846-4860[Abstract/Free Full Text]. -
Rosene DL,
Van Hoesen GW
(1987)
The hippocampal formation of the primate brain a review of some comparative aspects of cytoarchitecture and connections.
In: The cerebral cortex, Vol 6 (Jones EG,
Peters A,
eds), pp 345-456. New York: Plenum.
-
Ruppersberg JP,
Schroter KH,
Sakman B,
Stocker M,
Sewing S,
Pongs O
(1990)
Heteromultimeric channels formed by rat brain potassium-channel proteins.
Nature
345:535-537[Medline].
-
Safronov BV,
Kampe K,
Vogel W
(1993)
Single voltage-dependent potassium channels in rat peripheral nerve membrane.
J Physiol (Lond)
460:675-691[Abstract/Free Full Text].
-
Scannevin RH,
Trimmer JS
(1997)
Cytoplasmic domains of voltage-sensitive K+ channels involved in mediating protein-protein interactions.
Biochem Biophys Res Commun
232:585-589[Web of Science][Medline].
-
Scannevin RH,
Murakoshi H,
Rhodes KJ,
Trimmer JS
(1996)
Identification of a cytoplasmic domain important in the polarized expression and clustering of the Kv2.1 K+ channel.
J Cell Biol
135:1619-1632[Abstract/Free Full Text].
-
Scott VE,
Muniz ZM,
Sewing S,
Lichtinghagen R,
Parcej DN,
Pongs O,
Dolly JO
(1994a)
Antibodies specific for distinct Kv subunits unveil a hetero-oligomeric basis for subtypes of alpha-dendrotoxin-sensitive K+ channels in bovine brain.
Biochem J
33:1617-1623.
-
Scott VE,
Rettig J,
Parcej DN,
Keen JN,
Findlay JB,
Pongs O,
Dolly JO
(1994b)
Primary structure of a
-subunit of
-dendrotoxin-sensitive K+ channels from bovine brain.
Proc Natl Acad Sci USA
91:1637-1641[Abstract/Free Full Text]. -
Sewing S,
Roeper J,
Pongs O
(1996)
Kv
1 subunit binding specific for Shaker-related potassium channel
subunits.
Neuron
16:455-463[Web of Science][Medline]. -
Sheng M,
Kim E
(1996)
Ion channel associated proteins.
Curr Opin Neurobiol
6:602-608[Web of Science][Medline].
-
Sheng M,
Liao YJ,
Jan YN,
Jan LY
(1993)
Presynaptic -current based on heteromultimeric K+ channels detected in vivo.
Nature
365:72-75[Medline].
-
Sheng M,
Tsaur ML,
Jan YN,
Jan LY
(1994)
Contrasting subcellular localization of the Kv1.2 K+ channel subunits in different neurons of rat brain.
J Neurosci
14:2408-2417[Abstract].
-
Shi G,
Kleinklaus AK,
Marrion NV,
Trimmer JS
(1994)
Properties of Kv2.1 K+ channels expressed in transfected mammalian cells.
J Biol Chem
269:23204-23211[Abstract/Free Full Text].
-
Shi G,
Nakahira K,
Hammond S,
Rhodes KJ,
Schechter LE,
Trimmer JS
(1996)
-subunits promote K+ channel surface expression through effects early in biosynthesis.
Neuron
16:843-852[Web of Science][Medline]. -
Stansfeld CE,
Feltz A
(1988)
Dendrotoxin-sensitive K+ channels in dorsal root ganglion cells.
Neurosci Lett
93:49-55[Web of Science][Medline].
-
Trimmer JS
(1991)
Immunological identification and characterization of a delayed rectifier K+ channel in rat brain.
Proc Natl Acad Sci USA
88:10764-10768[Abstract/Free Full Text].
-
Veh RW,
Lichtinghagen R,
Sewing S,
Wunder F,
Grumbach IM,
Pongs O
(1995)
Immunohistochemical localization of five members of the Kv1 family subunits: contrasting subcellular locations and neuron-specific co-localization in rat brain.
Eur J Neurosci
7:2189-2205[Web of Science][Medline].
-
Wang H,
Kunkel DD,
Martin TM,
Schwartzkroin PA,
Tempel BL
(1993)
Heteromultimeric K+ channels in terminal and juxtaparanodal regions of neurons.
Nature
365:75-79[Medline].
-
Wang H,
Kunkel DD,
Martin TM,
Schwartzkroin PA,
Tempel BL
(1994)
Localization of Kv1.1 and Kv1.2, two K channel proteins, to synaptic terminals, somata, and dendrites in the mouse brain.
J Neurosci
14:4588-4599[Abstract].
-
Yu W,
Xu J,
Li M
(1996)
Inactivation of Kv1 potassium channels by the
-subunit, Kv
1, involves Kv
1 binding to NAB, a region that mediates subfamily-specific subunit assembly.
Neuron
16:441-453[Web of Science][Medline].
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[Abstract]
[Full Text]
[PDF]
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J. Maffie and B. Rudy
Weighing the evidence for a ternary protein complex mediating A-type K+ currents in neurons
J. Physiol.,
December 1, 2008;
586(23):
5609 - 5623.
[Abstract]
[Full Text]
[PDF]
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R. H. Pineda, C. S. Knoeckel, A. D. Taylor, A. Estrada-Bernal, and A. B. Ribera
Kv1 Potassium Channel Complexes In Vivo Require Kv{beta}2 Subunits in Dorsal Spinal Neurons
J Neurophysiol,
October 1, 2008;
100(4):
2125 - 2136.
[Abstract]
[Full Text]
[PDF]
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H. Vacher, D. P. Mohapatra, and J. S. Trimmer
Localization and Targeting of Voltage-Dependent Ion Channels in Mammalian Central Neurons
Physiol Rev,
October 1, 2008;
88(4):
1407 - 1447.
[Abstract]
[Full Text]
[PDF]
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A. Lorincz and Z. Nusser
Specificity of Immunoreactions: The Importance of Testing Specificity in Each Method
J. Neurosci.,
September 10, 2008;
28(37):
9083 - 9086.
[Full Text]
[PDF]
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H. Soh and S. A. N. Goldstein
ISA Channel Complexes Include Four Subunits Each of DPP6 and Kv4.2
J. Biol. Chem.,
May 30, 2008;
283(22):
15072 - 15077.
[Abstract]
[Full Text]
[PDF]
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K. J. Rhodes and J. S. Trimmer
Antibody-based Validation of CNS Ion Channel Drug Targets
J. Gen. Physiol.,
May 1, 2008;
131(5):
407 - 413.
[Full Text]
[PDF]
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J.-W. Yang, H. Vacher, K.-S. Park, E. Clark, and J. S. Trimmer
Trafficking-dependent phosphorylation of Kv1.2 regulates voltage-gated potassium channel cell surface expression
PNAS,
December 11, 2007;
104(50):
20055 - 20060.
[Abstract]
[Full Text]
[PDF]
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H. M. Brew, J. X. Gittelman, R. S. Silverstein, T. D. Hanks, V. P. Demas, L. C. Robinson, C. A. Robbins, J. McKee-Johnson, S. Y. Chiu, A. Messing, et al.
Seizures and Reduced Life Span in Mice Lacking the Potassium Channel Subunit Kv1.2, but Hypoexcitability and Enlarged Kv1 Currents in Auditory Neurons
J Neurophysiol,
September 1, 2007;
98(3):
1501 - 1525.
[Abstract]
[Full Text]
[PDF]
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A. E. Metz, N. Spruston, and M. Martina
Dendritic D-type potassium currents inhibit the spike afterdepolarization in rat hippocampal CA1 pyramidal neurons
J. Physiol.,
May 15, 2007;
581(1):
175 - 187.
[Abstract]
[Full Text]
[PDF]
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P. Imbrici, M. C. D'Adamo, A. Cusimano, and M. Pessia
Episodic ataxia type 1 mutation F184C alters Zn2+-induced modulation of the human K+ channel Kv1.4-Kv1.1/Kvbeta1.1
Am J Physiol Cell Physiol,
February 1, 2007;
292(2):
C778 - C787.
[Abstract]
[Full Text]
[PDF]
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M. Menegola and J. S. Trimmer
Unanticipated Region- and Cell-Specific Downregulation of Individual KChIP Auxiliary Subunit Isotypes in Kv4.2 Knock-Out Mouse Brain.
J. Neurosci.,
November 22, 2006;
26(47):
12137 - 12142.
[Abstract]
[Full Text]
[PDF]
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K. Vervaeke, N. Gu, C. Agdestein, H. Hu, and J. F. Storm
Kv7/KCNQ/M-channels in rat glutamatergic hippocampal axons and their role in regulation of excitability and transmitter release
J. Physiol.,
October 1, 2006;
576(1):
235 - 256.
[Abstract]
[Full Text]
[PDF]
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A. Hiraga, S. Kuwabara, S. Hayakawa, S. Ito, K. Arimura, K. Kanai, T. Yonezu, and T. Hattori
Voltage-gated potassium channel antibody-associated encephalitis with basal ganglia lesions
Neurology,
June 13, 2006;
66(11):
1780 - 1781.
[Full Text]
[PDF]
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K. A. Kleopa, L. B. Elman, B. Lang, A. Vincent, and S. S. Scherer
Neuromyotonia and limbic encephalitis sera target mature Shaker-type K+ channels: subunit specificity correlates with clinical manifestations
Brain,
June 1, 2006;
129(6):
1570 - 1584.
[Abstract]
[Full Text]
[PDF]
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D. Guan, J. C. F. Lee, T. Tkatch, D. J. Surmeier, W. E. Armstrong, and R. C. Foehring
Expression and biophysical properties of Kv1 channels in supragranular neocortical pyramidal neurones
J. Physiol.,
March 1, 2006;
571(2):
371 - 389.
[Abstract]
[Full Text]
[PDF]
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M. C. Inda, J. DeFelipe, and A. Munoz
Voltage-gated ion channels in the axon initial segment of human cortical pyramidal cells and their relationship with chandelier cells
PNAS,
February 21, 2006;
103(8):
2920 - 2925.
[Abstract]
[Full Text]
[PDF]
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S. Khavandgar, J. T. Walter, K. Sageser, and K. Khodakhah
Kv1 channels selectively prevent dendritic hyperexcitability in rat Purkinje cells
J. Physiol.,
December 1, 2005;
569(2):
545 - 557.
[Abstract]
[Full Text]
[PDF]
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N. Decher, P. Kumar, T. Gonzalez, V. Renigunta, and M. C. Sanguinetti
Structural Basis for Competition between Drug Binding and Kv{beta}1.3 Accessory Subunit-Induced N-Type Inactivation of Kv1.5 Channels
Mol. Pharmacol.,
October 1, 2005;
68(4):
995 - 1005.
[Abstract]
[Full Text]
[PDF]
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S. Kourrich, C. Manrique, P. Salin, and C. Mourre
Transient hippocampal down-regulation of Kv1.1 subunit mRNA during associative learning in rats
Learn. Mem.,
September 1, 2005;
12(5):
511 - 519.
[Abstract]
[Full Text]
[PDF]
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R. Vicente, A. Escalada, C. Soler, M. Grande, A. Celada, M. M. Tamkun, C. Solsona, and A. Felipe
Pattern of Kv{beta} Subunit Expression in Macrophages Depends upon Proliferation and the Mode of Activation
J. Immunol.,
April 15, 2005;
174(8):
4736 - 4744.
[Abstract]
[Full Text]
[PDF]
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F. Aimond, S. P. Kwak, K. J. Rhodes, and J. M. Nerbonne
Accessory Kv{beta}1 Subunits Differentially Modulate the Functional Expression of Voltage-Gated K+ Channels in Mouse Ventricular Myocytes
Circ. Res.,
March 4, 2005;
96(4):
451 - 458.
[Abstract]
[Full Text]
[PDF]
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C. Marionneau, B. Couette, J. Liu, H. Li, M. E. Mangoni, J. Nargeot, M. Lei, D. Escande, and S. Demolombe
Specific pattern of ionic channel gene expression associated with pacemaker activity in the mouse heart
J. Physiol.,
January 1, 2005;
562(1):
223 - 234.
[Abstract]
[Full Text]
[PDF]
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T. Shevchenko, R. Teruyama, and W. E. Armstrong
High-Threshold, Kv3-Like Potassium Currents in Magnocellular Neurosecretory Neurons and Their Role in Spike Repolarization
J Neurophysiol,
November 1, 2004;
92(5):
3043 - 3055.
[Abstract]
[Full Text]
[PDF]
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K. J. Rhodes, K. I. Carroll, M. A. Sung, L. C. Doliveira, M. M. Monaghan, S. L. Burke, B. W. Strassle, L. Buchwalder, M. Menegola, J. Cao, et al.
KChIPs and Kv4 {alpha} Subunits as Integral Components of A-Type Potassium Channels in Mammalian Brain
J. Neurosci.,
September 8, 2004;
24(36):
7903 - 7915.
[Abstract]
[Full Text]
[PDF]
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Z.-H. Zhang, K. J. Rhodes, W. E. Childers, T. M. Argentieri, and Q. Wang
"Disinactivation" of N-type Inactivation of Voltage-gated K Channels by an Erbstatin Analogue
J. Biol. Chem.,
July 9, 2004;
279(28):
29226 - 29230.
[Abstract]
[Full Text]
[PDF]
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W. Shen, S. Hernandez-Lopez, T. Tkatch, J. E. Held, and D. J. Surmeier
Kv1.2-Containing K+ Channels Regulate Subthreshold Excitability of Striatal Medium Spiny Neurons
J Neurophysiol,
March 1, 2004;
91(3):
1337 - 1349.
[Abstract]
[Full Text]
[PDF]
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L. A. Kim, J. Furst, M. H. Butler, S. Xu, N. Grigorieff, and S. A. N. Goldstein
Ito Channels Are Octomeric Complexes with Four Subunits of Each Kv4.2 and K+ Channel-interacting Protein 2
J. Biol. Chem.,
February 13, 2004;
279(7):
5549 - 5554.
[Abstract]
[Full Text]
[PDF]
|
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S. Poliak, D. Salomon, H. Elhanany, H. Sabanay, B. Kiernan, L. Pevny, C. L. Stewart, X. Xu, S.-Y. Chiu, P. Shrager, et al.
Juxtaparanodal clustering of Shaker-like K+ channels in myelinated axons depends on Caspr2 and TAG-1
J. Cell Biol.,
September 15, 2003;
162(6):
1149 - 1160.
[Abstract]
[Full Text]
[PDF]
|
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J. Zhu, I. Watanabe, B. Gomez, and W. B. Thornhill
Heteromeric Kv1 Potassium Channel Expression: AMINO ACID DETERMINANTS INVOLVED IN PROCESSING AND TRAFFICKING TO THE CELL SURFACE
J. Biol. Chem.,
July 3, 2003;
278(28):
25558 - 25567.
[Abstract]
[Full Text]
[PDF]
|
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P. D Dodson, B. Billups, Z. Rusznak, G. Szucs, M. C Barker, and I. D Forsythe
Presynaptic rat Kv1.2 channels suppress synaptic terminal hyperexcitability following action potential invasion
J. Physiol.,
July 1, 2003;
550(1):
27 - 33.
[Abstract]
[Full Text]
[PDF]
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J. S. Rothman and P. B. Manis
Kinetic Analyses of Three Distinct Potassium Conductances in Ventral Cochlear Nucleus Neurons
J Neurophysiol,
June 1, 2003;
89(6):
3083 - 3096.
[Abstract]
[Full Text]
[PDF]
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Y. M. Leung, Y. Kang, X. Gao, F. Xia, H. Xie, L. Sheu, S. Tsuk, I. Lotan, R. G. Tsushima, and H. Y. Gaisano
Syntaxin 1A Binds to the Cytoplasmic C Terminus of Kv2.1 to Regulate Channel Gating and Trafficking
J. Biol. Chem.,
May 2, 2003;
278(19):
17532 - 17538.
[Abstract]
[Full Text]
[PDF]
|
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H. M Brew, J. L Hallows, and B. L Tempel
Hyperexcitability and reduced low threshold potassium currents in auditory neurons of mice lacking the channel subunit Kv1.1
J. Physiol.,
April 1, 2003;
548(1):
1 - 20.
[Abstract]
[Full Text]
[PDF]
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M. N. Rasband, E. W. Park, D. Zhen, M. I. Arbuckle, S. Poliak, E. Peles, S. G.N. Grant, and J. S. Trimmer
Clustering of neuronal potassium channels is independent of their interaction with PSD-95
J. Cell Biol.,
November 25, 2002;
159(4):
663 - 672.
[Abstract]
[Full Text]
[PDF]
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B. Maylie, E. Bissonnette, M. Virk, J. P. Adelman, and J. G. Maylie
Episodic Ataxia Type 1 Mutations in the Human Kv1.1 Potassium Channel Alter hKvbeta 1-Induced N-Type Inactivation
J. Neurosci.,
June 15, 2002;
22(12):
4786 - 4793.
[Abstract]
[Full Text]
[PDF]
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S. Akhtar, O. Shamotienko, M. Papakosta, F. Ali, and J. O. Dolly
Characteristics of Brain Kv1 Channels Tailored to Mimic Native Counterparts by Tandem Linkage of alpha Subunits. IMPLICATIONS FOR K+ CHANNELOPATHIES
J. Biol. Chem.,
May 3, 2002;
277(19):
16376 - 16382.
[Abstract]
[Full Text]
[PDF]
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J. P. Giblin, Y. Cui, L. H. Clapp, and A. Tinker
Assembly Limits the Pharmacological Complexity of ATP-sensitive Potassium Channels
J. Biol. Chem.,
April 12, 2002;
277(16):
13717 - 13723.
[Abstract]
[Full Text]
[PDF]
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K. McCormack, J. X. Connor, L. Zhou, L. L. Ho, B. Ganetzky, S.-Y. Chiu, and A. Messing
Genetic Analysis of the Mammalian K+ Channel beta Subunit Kvbeta 2 (Kcnab2)
J. Biol. Chem.,
April 5, 2002;
277(15):
13219 - 13228.
[Abstract]
[Full Text]
[PDF]
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C. R. Campomanes, K. I. Carroll, L. N. Manganas, M. E. Hershberger, B. Gong, D. E. Antonucci, K. J. Rhodes, and J. S. Trimmer
Kvbeta Subunit Oxidoreductase Activity and Kv1 Potassium Channel Trafficking
J. Biol. Chem.,
March 1, 2002;
277(10):
8298 - 8305.
[Abstract]
[Full Text]
[PDF]
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M. H. Holmqvist, J. Cao, R. Hernandez-Pineda, M. D. Jacobson, K. I. Carroll, M. A. Sung, M. Betty, P. Ge, K. J. Gilbride, M. E. Brown, et al.
Elimination of fast inactivation in Kv4 A-type potassium channels by an auxiliary subunit domain
PNAS,
January 22, 2002;
99(2):
1035 - 1040.
[Abstract]
[Full Text]
[PDF]
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H. Hu, L.-R. Shao, S. Chavoshy, N. Gu, M. Trieb, R. Behrens, P. Laake, O. Pongs, H. G. Knaus, O. P. Ottersen, et al.
Presynaptic Ca2+-Activated K+ Channels in Glutamatergic Hippocampal Terminals and Their Role in Spike Repolarization and Regulation of Transmitter Release
J. Neurosci.,
December 15, 2001;
21(24):
9585 - 9597.
[Abstract]
[Full Text]
[PDF]
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R. Liguori, A. Vincent, L. Clover, P. Avoni, G. Plazzi, P. Cortelli, A. Baruzzi, T. Carey, P. Gambetti, E. Lugaresi, et al.
Morvan's syndrome: peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels
Brain,
December 1, 2001;
124(12):
2417 - 2426.
[Abstract]
[Full Text]
[PDF]
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V. Riazanski, A. Becker, J. Chen, D. Sochivko, A. Lie, O. D Wiestler, C. E Elger, and H. Beck
Functional and molecular analysis of transient voltage-dependent K+ currents in rat hippocampal granule cells
J. Physiol.,
December 1, 2001;
537(2):
391 - 406.
[Abstract]
[Full Text]
[PDF]
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M. N. Rasband, E. W. Park, T. W. Vanderah, J. Lai, F. Porreca, and J. S. Trimmer
Distinct potassium channels on pain-sensing neurons
PNAS,
November 6, 2001;
98(23):
13373 - 13378.
[Abstract]
[Full Text]
[PDF]
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J. Zhu, I. Watanabe, B. Gomez, and W. B. Thornhill
Determinants Involved in Kv1 Potassium Channel Folding in the Endoplasmic Reticulum, Glycosylation in the Golgi, and Cell Surface Expression
J. Biol. Chem.,
October 12, 2001;
276(42):
39419 - 39427.
[Abstract]
[Full Text]
[PDF]
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S. Poliak, L. Gollan, D. Salomon, E. O. Berglund, R. Ohara, B. Ranscht, and E. Peles
Localization of Caspr2 in Myelinated Nerves Depends on Axon-Glia Interactions and the Generation of Barriers along the Axon
J. Neurosci.,
October 1, 2001;
21(19):
7568 - 7575.
[Abstract]
[Full Text]
[PDF]
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M. M. Monaghan, J. S. Trimmer, and K. J. Rhodes
Experimental Localization of Kv1 Family Voltage-Gated K+ Channel {alpha} and {beta} Subunits in Rat Hippocampal Formation
J. Neurosci.,
August 15, 2001;
21(16):
5973 - 5983.
[Abstract]
[Full Text]
[PDF]
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M. N Rasband and P. Shrager
Ion channel sequestration in central nervous system axons
J. Physiol.,
May 15, 2000;
525(1):
63 - 73.
[Abstract]
[Full Text]
[PDF]
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G. Grosse, A. Draguhn, L. Hohne, R. Tapp, R. W. Veh, and G. Ahnert-Hilger
Expression of Kv1 Potassium Channels in Mouse Hippocampal Primary Cultures: Development and Activity-Dependent Regulation
J. Neurosci.,
March 1, 2000;
20(5):
1869 - 1882.
[Abstract]
[Full Text]
[PDF]
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T. Tkatch, G. Baranauskas, and D. J. Surmeier
Kv4.2 mRNA Abundance and A-Type K+ Current Amplitude Are Linearly Related in Basal Ganglia and Basal Forebrain Neurons
J. Neurosci.,
January 15, 2000;
20(2):
579 - 588.
[Abstract]
[Full Text]
[PDF]
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M. A. Lazaroff, A. D. Hofmann, and A. B. Ribera
Xenopus Embryonic Spinal Neurons Express Potassium Channel Kvbeta Subunits
J. Neurosci.,
December 15, 1999;
19(24):
10706 - 10715.
[Abstract]
[Full Text]
[PDF]
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C. Mourre, M. N. Chernova, M.-F. Martin-Eauclaire, R. Bessone, G. Jacquet, M. Gola, Seth. L. Alper, and M. Crest
Distribution in Rat Brain of Binding Sites of Kaliotoxin, a Blocker of Kv1.1 and Kv1.3 alpha -Subunits
J. Pharmacol. Exp. Ther.,
December 1, 1999;
291(3):
943 - 952.
[Abstract]
[Full Text]
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X. Zhang, J. Ma, and G. A. Berkowitz
Evaluation of Functional Interaction between K+ Channel alpha - and beta -Subunits and Putative Inactivation Gating by Co-Expression in Xenopus laevis Oocytes
Plant Physiology,
November 1, 1999;
121(3):
995 - 1002.
[Abstract]
[Full Text]
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F. Lehmann-Horn and K. Jurkat-Rott
Voltage-Gated Ion Channels and Hereditary Disease
Physiol Rev,
October 1, 1999;
79(4):
1317 - 1372.
[Abstract]
[Full Text]
[PDF]
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G. Baranauskas, T. Tkatch, and D. J. Surmeier
Delayed Rectifier Currents in Rat Globus Pallidus Neurons Are Attributable to Kv2.1 and Kv3.1/3.2 K+ Channels
J. Neurosci.,
August 1, 1999;
19(15):
6394 - 6404.
[Abstract]
[Full Text]
[PDF]
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A. Epperson, H. P. Bonner, S. M. Ward, W. J. Hatton, K. K. Bradley, M. E. Bradley, J. S. Trimmer, and B. Horowitz
Molecular diversity of KV alpha - and beta -subunit expression in canine gastrointestinal smooth muscles
Am J Physiol Gastrointest Liver Physiol,
July 1, 1999;
277(1):
G127 - G136.
[Abstract]
[Full Text]
[PDF]
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M. T. Perez-Garcia, J. R. Lopez-Lopez, and C. Gonzalez
Kv{beta}1.2 Subunit Coexpression in HEK293 Cells Confers O2 Sensitivity to Kv4.2 but not to Shaker Channels
J. Gen. Physiol.,
June 1, 1999;
113(6):
897 - 907.
[Abstract]
[Full Text]
[PDF]
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H. Murakoshi and J. S. Trimmer
Identification of the Kv2.1 K+ Channel as a Major Component of the Delayed Rectifier K+ Current in Rat Hippocampal Neurons
J. Neurosci.,
March 1, 1999;
19(5):
1728 - 1735.
[Abstract]
[Full Text]
[PDF]
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I. Vabnick, J. S. Trimmer, T. L. Schwarz, S. R. Levinson, D. Risal, and P. Shrager
Dynamic Potassium Channel Distributions during Axonal Development Prevent Aberrant Firing Patterns
J. Neurosci.,
January 15, 1999;
19(2):
747 - 758.
[Abstract]
[Full Text]
[PDF]
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B. Engeland, A. Neu, J. Ludwig, J. Roeper, and O. Pongs
Cloning and functional expression of rat ether-a-go-go-like K+ channel genes
J. Physiol.,
December 15, 1998;
513(3):
647 - 654.
[Abstract]
[Full Text]
[PDF]
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S. J. Lombardi, A. Truong, P. Spence, K. J. Rhodes, and P. G. Jones
Structure-Activity Relationships of the Kvbeta 1 Inactivation Domain and Its Putative Receptor Probed Using Peptide Analogs of Voltage-gated Potassium Channel alpha - and beta -Subunits
J. Biol. Chem.,
November 13, 1998;
273(46):
30092 - 30096.
[Abstract]
[Full Text]
[PDF]
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E A Accili, Y A Kuryshev, B A Wible, and A M Brown
Separable effects of human Kv{beta}1.2 N- and C-termini on inactivation and expression of human Kv1.4
J. Physiol.,
October 15, 1998;
512(2):
325 - 336.
[Abstract]
[Full Text]
[PDF]
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K. F. Raab-Graham and C. A. Vandenberg
Tetrameric Subunit Structure of the Native Brain Inwardly Rectifying Potassium Channel Kir 2.2
J. Biol. Chem.,
July 31, 1998;
273(31):
19699 - 19707.
[Abstract]
[Full Text]
[PDF]
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L. N. Manganas and J. S. Trimmer
Subunit Composition Determines Kv1 Potassium Channel Surface Expression
J. Biol. Chem.,
September 15, 2000;
275(38):
29685 - 29693.
[Abstract]
[Full Text]
[PDF]
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L. N. Manganas, S. Akhtar, D. E. Antonucci, C. R. Campomanes, J. O. Dolly, and J. S. Trimmer
Episodic Ataxia Type-1 Mutations in the Kv1.1 Potassium Channel Display Distinct Folding and Intracellular Trafficking Properties
J. Biol. Chem.,
December 21, 2001;
276(52):
49427 - 49434.
[Abstract]
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L. N. Manganas, Q. Wang, R. H. Scannevin, D. E. Antonucci, K. J. Rhodes, and J. S. Trimmer
Identification of a trafficking determinant localized to the Kv1 potassium channel pore
PNAS,
November 20, 2001;
98(24):
14055 - 14059.
[Abstract]
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K. S. Thorneloe, T. T. Chen, P. M. Kerr, E. F. Grier, B. Horowitz, W. C. Cole, and M. P. Walsh
Molecular Composition of 4-Aminopyridine-Sensitive Voltage-Gated K+ Channels of Vascular Smooth Muscle
Circ. Res.,
November 23, 2001;
89(11):
1030 - 1037.
[Abstract]
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