WWW.JNEUROSCI.ORG
-
The Journal of Neuroscience AAN Call for Abstracts
QUICK SEARCH:   [advanced]


     
-


HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit an eLetter
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (36)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ramanathan, K.
Right arrow Articles by Fuchs, P. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ramanathan, K.
Right arrow Articles by Fuchs, P. A.

 Previous Article  |  Next Article 

The Journal of Neuroscience, March 1, 2000, 20(5):1675-1684

beta Subunits Modulate Alternatively Spliced, Large Conductance, Calcium-Activated Potassium Channels of Avian Hair Cells

Krishnan Ramanathan, Timothy H. Michael, and Paul A. Fuchs

The Center for Hearing Sciences, Department of Biomedical Engineering and Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2195

Electrical tuning confers frequency selectivity onto sensory hair cells in the auditory periphery of frogs, turtles, and chicks. The resonant frequency is determined in large part by the number and kinetics of large conductance, calcium-activated potassium (BK) channels. BK channels in hair cells are encoded by the alternatively spliced slo gene and may include an accessory beta  subunit. Here we examine the origins of kinetic variability among BK channels by heterologous expression of avian cochlear slo cDNAs. Four alternatively spliced forms of the slo-alpha gene from chick hair cells were co-expressed with accessory beta  subunits (from quail cochlea) by transient transfection of human embryonic kidney 293 cells. Addition of the beta  subunit increased steady-state calcium affinity, raised the Hill coefficient for calcium binding, and slowed channel deactivation rates, resulting in eight functionally distinct channels. For example, a naturally occurring splice variant containing three additional exons deactivated 20-fold more slowly when combined with beta . Deactivation kinetics were used to predict tuning frequencies and thus tonotopic location if hair cells were endowed with each of the expressed channels. All beta -containing channels were predicted to lie within the apical (low-frequency) 30% of the epithelium, consistent with previous in situ hybridization studies. Individual slo-alpha exons would be found anywhere within the apical 70%, depending on the presence of beta , and other alternative exons. Alternative splicing of the slo-alpha channel message provides intrinsic variability in gating kinetics that is expanded to a wider range of tuning by modulation with beta  subunits.

Key words: calcium-activated potassium channel; electrical tuning; beta subunits; alternative splicing; cochlea; hair cell; avian; chick

Copyright © 2000 Society for Neuroscience  0270-6474/00/2051675-10$05.00/0


This article has been cited by other articles:


Home page
 J. Neurophysiol.Home page
E. Y. Kim, S. Zou, L. D. Ridgway, and S. E. Dryer
beta1-Subunits Increase Surface Expression of a Large-Conductance Ca2+-Activated K+ Channel Isoform
J Neurophysiol, May 1, 2007; 97(5): 3508 - 3516.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
K. T. Blackwell
Ionic Currents Underlying Difference in Light Response Between Type A and Type B Photoreceptors
J Neurophysiol, May 1, 2006; 95(5): 3060 - 3072.
[Abstract] [Full Text] [PDF]

Home page
 J. Exp. Biol.Home page
M. R. Keyser and J. L. Witten
Calcium-activated potassium channel of the tobacco hornworm, Manduca sexta: molecular characterization and expression analysis
J. Exp. Biol., November 1, 2005; 208(21): 4167 - 4179.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
W. J. Moody and M. M. Bosma
Ion Channel Development, Spontaneous Activity, and Activity-Dependent Development in Nerve and Muscle Cells
Physiol Rev, July 1, 2005; 85(3): 883 - 941.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
I. Fukui and H. Ohmori
Tonotopic Gradients of Membrane and Synaptic Properties for Neurons of the Chicken Nucleus Magnocellularis
J. Neurosci., August 25, 2004; 24(34): 7514 - 7523.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
W. Marcotti, S. L. Johnson, and C. J. Kros
Effects of intracellular stores and extracellular Ca2+ on Ca2+-activated K+ currents in mature mouse inner hair cells
J. Physiol., June 1, 2004; 557(2): 613 - 633.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
F. Lesage, H. Hibino, and A. J. Hudspeth
Association of {beta}-catenin with the {alpha}-subunit of neuronal large-conductance Ca2+-activated K+ channels
PNAS, January 13, 2004; 101(2): 671 - 675.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
P. V. Lovell, J. T. King, and D. P. McCobb
Acute Modulation of Adrenal Chromaffin Cell BK Channel Gating and Cell Excitability by Glucocorticoids
J Neurophysiol, January 1, 2004; 91(1): 561 - 570.
[Abstract] [Full Text]

Home page
 Proc. Natl. Acad. Sci. USAHome page
X. Qian and K. L. Magleby
{beta}1 subunits facilitate gating of BK channels by acting through the Ca2+, but not the Mg2+, activating mechanisms
PNAS, August 19, 2003; 100(17): 10061 - 10066.
[Abstract] [Full Text] [PDF]

Home page
 Biophys. JHome page
V. Avdonin, X. D. Tang, and T. Hoshi
Stimulatory Action of Internal Protons on Slo1 BK Channels
Biophys. J., May 1, 2003; 84(5): 2969 - 2980.
[Abstract] [Full Text] [PDF]

Home page
 J. Gen. Physiol.Home page
X. Qian, C. M. Nimigean, X. Niu, B. L. Moss, and K. L. Magleby
Slo1 Tail Domains, but Not the Ca2+ Bowl, Are Required for the {beta}1 Subunit to Increase the Apparent Ca2+ Sensitivity of BK Channels
J. Gen. Physiol., November 25, 2002; 120(6): 829 - 843.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. Martin-Caraballo and S. E. Dryer
Activity- and Target-Dependent Regulation of Large-Conductance Ca2+-Activated K+ Channels in Developing Chick Lumbar Motoneurons
J. Neurosci., January 1, 2002; 22(1): 73 - 81.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
S. Parameshwaran, C. E. Carr, and T. M. Perney
Expression of the Kv3.1 Potassium Channel in the Avian Auditory Brainstem
J. Neurosci., January 15, 2001; 21(2): 485 - 494.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
J. S. Cameron and S. E. Dryer
BK-Type KCa Channels in Two Parasympathetic Cell Types: Differences in Kinetic Properties and Developmental Expression
J Neurophysiol, December 1, 2000; 84(6): 2767 - 2776.
[Abstract] [Full Text] [PDF]


-

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help
-
Copyright 2008 by Society for Neuroscience ONLINE ISSN: 1529-2401
-