 |
 Previous Article
Journal of Neuroscience, Vol 13, 4997-5007, Copyright © 1993 by Society for Neuroscience
Relative properties and localizations of synaptic vesicle protein isoforms: the case of the synaptophysins
EM Fykse, K Takei, C Walch-Solimena, M Geppert, R Jahn, P De Camilli and TC Sudhof
Department of Molecular Genetics, University of Texas Southwestern Medical School, Dallas 75235.
Synaptophysins are abundant synaptic vesicle proteins present in two forms:
synaptophysin, also referred to as synaptophysin I (abbreviated syp I), and
synaptoporin, also referred to as synaptophysin II (abbreviated syp II). In
the present study, the properties and localizations of syp I and syp II
were investigated to shed light on their relative functions. Our results
reveal that syp II, similar to syp I, is an abundant, N-glycosylated
membrane protein that is part of a heteromultimeric complex in synaptic
vesicle membranes. Cross-linking studies indicate that syp II is linked to
a low-molecular-weight protein in this complex as has been observed before
for syp I. Furthermore, after transfection into CHO cells, syp II, similar
to syp I, is targeted to the receptor-mediated endocytosis pathway.
Immunocytochemistry of rat brain sections reveals that syp II expression is
highly heterogeneous, with high concentrations of syp II only in selected
neuronal populations, whereas syp I is more homogeneously expressed in most
nerve terminals. In general, nerve terminals expressing syp II also express
syp I. In addition to high levels of syp II observed in selected neurons, a
rostrocaudal gradient of syp II expression was observed in the cerebellar
cortex. Immunoelectron microscopy confirmed that syp II is localized to
synaptic vesicles. Immunoprecipitations of synaptic vesicles from rat brain
with antibodies to syp I demonstrated that syp II is colocalized with syp I
on the same vesicles. However, after detergent solubilization, no
coimmunoprecipitations of the two proteins were observed, suggesting that
they are not complexed with each other although they are on the same
vesicles. Together our results demonstrate that syp I and syp II have
similar properties and are present on the same synaptic vesicles but do not
coassemble. The presence of the two proteins in the same nerve terminal
suggests that they have similar but nonidentical functions and that the
relative abundance of the two proteins may contribute to the functional
heterogeneity of nerve terminals.
This article has been cited by other articles:
|
|
|
|
 
R. V. Sillitoe, M. A. Benson, D. J. Blake, and R. Hawkes
Abnormal Dysbindin Expression in Cerebellar Mossy Fiber Synapses in the mdx Mouse Model of Duchenne Muscular Dystrophy
J. Neurosci.,
July 23, 2003;
23(16):
6576 - 6585.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. M. Schluter, M. Khvotchev, R. Jahn, and T. C. Sudhof
Localization Versus Function of Rab3 Proteins. EVIDENCE FOR A COMMON REGULATORY ROLE IN CONTROLLING FUSION
J. Biol. Chem.,
October 18, 2002;
277(43):
40919 - 40929.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. J. Shin, R. A. Fricker-Gates, F. A. Perez, B. R. Leavitt, D. Zurakowski, and J. D. Macklis
Transplanted Neuroblasts Differentiate Appropriately into Projection Neurons with Correct Neurotransmitter and Receptor Phenotype in Neocortex Undergoing Targeted Projection Neuron Degeneration
J. Neurosci.,
October 1, 2000;
20(19):
7404 - 7416.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. D. Smith, M. M. Adams, M. Gallagher, J. H. Morrison, and P. R. Rapp
Circuit-Specific Alterations in Hippocampal Synaptophysin Immunoreactivity Predict Spatial Learning Impairment in Aged Rats
J. Neurosci.,
September 1, 2000;
20(17):
6587 - 6593.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Takamori, D. Riedel, and R. Jahn
Immunoisolation of GABA-Specific Synaptic Vesicles Defines a Functionally Distinct Subset of Synaptic Vesicles
J. Neurosci.,
July 1, 2000;
20(13):
4904 - 4911.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. Fernandez-Chacon, G. A. de Toledo, R. E. Hammer, and T. C. Sudhof
Analysis of SCAMP1 Function in Secretory Vesicle Exocytosis by Means of Gene Targeting in Mice
J. Biol. Chem.,
November 12, 1999;
274(46):
32551 - 32554.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
O. M. Schluter, E. Schnell, M. Verhage, T. Tzonopoulos, R. A. Nicoll, R. Janz, R. C. Malenka, M. Geppert, and T. C. Sudhof
Rabphilin Knock-Out Mice Reveal That Rabphilin Is Not Required for Rab3 Function in Regulating Neurotransmitter Release
J. Neurosci.,
July 15, 1999;
19(14):
5834 - 5846.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Sugita, R. Janz, and T. C. Sudhof
Synaptogyrins Regulate Ca2+-dependent Exocytosis in PC12 Cells
J. Biol. Chem.,
July 2, 1999;
274(27):
18893 - 18901.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Khvotchev and T. C. Sudhof
Newly Synthesized Phosphatidylinositol Phosphates Are Required for Synaptic Norepinephrine but Not Glutamate or gamma -Aminobutyric Acid (GABA) Release
J. Biol. Chem.,
August 21, 1998;
273(34):
21451 - 21454.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Wigge, K. Köhler, Y. Vallis, C. A. Doyle, D. Owen, S. P. Hunt, and H. T. McMahon
Amphiphysin Heterodimers: Potential Role in Clathrin-mediated Endocytosis
Mol. Biol. Cell,
October 1, 1997;
8(10):
2003 - 2015.
[Abstract]
[Full Text]
|
|
|
|
|
|
|
R. Leube
The topogenic fate of the polytopic transmembrane proteins, synaptophysin and connexin, is determined by their membrane-spanning domains
J. Cell Sci.,
January 3, 1995;
108(3):
883 - 894.
[Abstract]
[PDF]
|
|
|
|
|
|
|
L. Tarsa and Y. Goda
Synaptophysin regulates activity-dependent synapse formation in cultured hippocampal neurons
PNAS,
January 22, 2002;
99(2):
1012 - 1016.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
