| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J Neurophysiol (February 1, 2003). 10.1152/jn.00482.2002
Submitted on Submitted 1 July 2002; accepted in final form 12 October 2002
REPORT
1Center for Neuroscience, Department of Otolaryngology, University of California, Davis, California 95616; 2Department of Otolaryngology, Beijing Hospital, Beijing, 10000, People's Republic of China; 3Synaptic Function Unit, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892
Song, Haitao,
Liping Nie,
Adrian Rodriguez-Contreras,
Zu-Hang Sheng, and
Ebenezer N. Yamoah.
Functional Interaction of Auxiliary Subunits and Synaptic
Proteins With CaV1.3 May Impart Hair Cell Ca2+
Current Properties. J. Neurophysiol. 89: 1143-1149, 2003. We assessed the
functional determinants of the properties of L-type
Ca2+ currents in hair cells by co-expressing the
pore-forming CaV1.3
1 subunit with the auxiliary subunits 
1A and/or
2
. Because Ca2+
channels in hair cells are poised to interact with synaptic proteins, we also co-expressed the
CaV1.31 subunit with
syntaxin, vesicle-associated membrane protein (VAMP), and synaptosome
associated protein of 25 kDa (SNAP25). Expression of the
CaV1.31 subunit in human
embryonic kidney cells (HEK 293) produced a dihydropyridine
(DHP)-sensitive Ca2+ current (peak current
density 
2.0 ± 0.2 pA/pF; n = 11). Co-expression with 1A and 2
subunits enhanced the magnitude of the current (peak current density:
CaV1.31 + 1A = 4.3 ± 0.8 pA/pF,
n = 10;
CaV1.31 + 1A + 2 = 4.1 ± 0.6 pA/pF, n = 9) and produced a leftward
shift of approximately 9 mV in the voltage-dependent activation of the
currents. Furthermore, co-expression of
CaV1.31 with
syntaxin/VAMP/SNAP resulted in at least a twofold increase in the peak
current density (4.7 ± 0.2 pA/pF; n = 11) and
reduced the extent of inactivation of the Ca2+
currents. Botulinum toxin, an inhibitor of syntaxin, accelerated the
inactivation profile of Ca2+ currents in hair
cells. Immunocytochemical data also indicated that the
Ca2+ channels and syntaxin are co-localized in
hair cells, suggesting there is functional interaction of the
CaV1.31 with auxiliary subunits and synaptic proteins, that may contribute to the distinct properties of the DHP-sensitive channels in hair cells.
This article has been cited by other articles:
|
|
 |
|
  P. S. Yang, B. A. Alseikhan, H. Hiel, L. Grant, M. X. Mori, W. Yang, P. A. Fuchs, and D. T. Yue Switching of Ca2+-Dependent Inactivation of CaV1.3 Channels by Calcium Binding Proteins of Auditory Hair Cells. J. Neurosci., October 18, 2006; 26(42): 10677 - 10689. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Shen, D. Yu, H. Hiel, P. Liao, D. T. Yue, P. A. Fuchs, and T. W. Soong Alternative Splicing of the CaV1.3 Channel IQ Domain, a Molecular Switch for Ca2+-Dependent Inactivation within Auditory Hair Cells. J. Neurosci., October 18, 2006; 26(42): 10690 - 10699. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. S. G. Geleoc, J. R. Risner, and J. R. Holt Developmental Acquisition of Voltage-Dependent Conductances and Sensory Signaling in Hair Cells of the Embryonic Mouse Inner Ear J. Neurosci., December 8, 2004; 24(49): 11148 - 11159. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Sidi, E. Busch-Nentwich, R. Friedrich, U. Schoenberger, and T. Nicolson gemini Encodes a Zebrafish L-Type Calcium Channel That Localizes at Sensory Hair Cell Ribbon Synapses J. Neurosci., April 28, 2004; 24(17): 4213 - 4223. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Rodriguez-Contreras and E. N. Yamoah Effects of Permeant Ion Concentrations on the Gating of L-Type Ca2+ Channels in Hair Cells Biophys. J., May 1, 2003; 84(5): 3457 - 3469. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
