|
||
The Journal of General Physiology, Vol 104, 1057-1077, Copyright © 1994 by The Rockefeller University Press
ARTICLES |
A Peretz, C Sandler, K Kirschfeld, RC Hardie and B Minke
Department of Physiology, Hadassah Medical School, Hebrew University, Jerusalem, Israel.
Invertebrate photoreceptors use the inositol-lipid signaling cascade for phototransduction. A useful approach to dissect this pathway and its regulation has been provided by the isolation of Drosophila visual mutants. We measured extracellular changes of Ca2+ [delta Ca2+]o in Drosophila retina using Ca(2+)-selective microelectrodes in both the transient receptor potential (trp) mutant, in which the calcium permeability of the light-sensitive channels is greatly diminished and in the inactivation-but-no-afterpotential C (inaC) mutant which lacks photoreceptor-specific protein kinase C (PKC). Illumination induced a decrease in extracellular [Ca2+] with kinetics and magnitude that changed with light intensity. Compared to wild-type, the light-induced decrease in [Ca2+]o (the Ca2+ signal) was diminished in trp but significantly enhanced in inaC. The enhanced Ca2+ signal was diminished in the double mutant inaC;trp indicating that the effect of the trp mutation overrides the enhancement observed in the absence of eye-PKC. We suggest that the decrease in [Ca2+]o reflects light-induced Ca2+ influx into the photoreceptors and that the trp mutation blocks a large fraction of this Ca2+ influx, while the absence of eye specific PKC leads to enhancement of light-induced Ca2+ influx. This suggestion was supported by Ca2+ measurements in isolated ommatidia loaded with the fluorescent Ca2+ indicator, Ca Green-5N, which indicated an approximately threefold larger light-induced increase in cellular Ca2+ in inaC relative to WT. Our observations are consistent with the hypothesis that TRP is a light activated Ca2+ channel and that the increased Ca2+ influx observed in the absence of PKC is mediated mainly via the TRP channel.
This article has been cited by other articles:
![]() |
N. E. Meyer, T. Joel-Almagor, S. Frechter, B. Minke, and A. Huber Subcellular translocation of the eGFP-tagged TRPL channel in Drosophila photoreceptors requires activation of the phototransduction cascade J. Cell Sci., June 15, 2006; 119(12): 2592 - 2603. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Chorna-Ornan, V. Tzarfaty, G. Ankri-Eliahoo, T. Joel-Almagor, N. E. Meyer, A. Huber, F. Payre, and B. Minke Light-regulated interaction of Dmoesin with TRP and TRPL channels is required for maintenance of photoreceptors J. Cell Biol., October 10, 2005; 171(1): 143 - 152. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Strange From Genes to Integrative Physiology: Ion Channel and Transporter Biology in Caenorhabditis elegans Physiol Rev, April 1, 2003; 83(2): 377 - 415. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. S. Hong, S. Park, C. Geng, K. Baek, J. D. Bowman, J. Yoon, and W. L. Pak Single Amino Acid Change in the Fifth Transmembrane Segment of the TRP Ca2+ Channel Causes Massive Degeneration of Photoreceptors J. Biol. Chem., September 6, 2002; 277(37): 33884 - 33889. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Minke and B. Cook TRP Channel Proteins and Signal Transduction Physiol Rev, April 1, 2002; 82(2): 429 - 472. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. C. Hardie Phototransduction in Drosophila melanogaster J. Exp. Biol., March 12, 2002; 204(20): 3403 - 3409. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. L. Walker, J. R. Hume, and B. Horowitz Differential expression and alternative splicing of TRP channel genes in smooth muscles Am J Physiol Cell Physiol, May 1, 2001; 280(5): C1184 - C1192. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Chorna-Ornan, T. Joel-Almagor, H. C. Ben-Ami, S. Frechter, B. Gillo, Z. Selinger, D. L. Gill, and B. Minke A Common Mechanism Underlies Vertebrate Calcium Signaling and Drosophila Phototransduction J. Neurosci., April 15, 2001; 21(8): 2622 - 2629. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Agam, M. von Campenhausen, S. Levy, H. C. Ben-Ami, B. Cook, K. Kirschfeld, and B. Minke Metabolic Stress Reversibly Activates the Drosophila Light-Sensitive Channels TRP and TRPL In Vivo J. Neurosci., August 1, 2000; 20(15): 5748 - 5755. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Yoon, H. C. Ben-Ami, Y. S. Hong, S. Park, L. L. R. Strong, J. Bowman, C. Geng, K. Baek, B. Minke, and W. L. Pak Novel Mechanism of Massive Photoreceptor Degeneration Caused by Mutations in the trp Gene of Drosophila J. Neurosci., January 15, 2000; 20(2): 649 - 659. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Haug-Collet, B. Pearson, R. Webel, R.T. Szerencsei, R.J. Winkfein, P.P.M. Schnetkamp, and N.J. Colley Cloning and Characterization of a Potassium-dependent Sodium/Calcium Exchanger in Drosophila J. Cell Biol., November 1, 1999; 147(3): 659 - 670. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. F. Stortkuhl, B. T. Hovemann, and J. R. Carlson Olfactory Adaptation Depends on the Trp Ca2+ Channel in Drosophila J. Neurosci., June 15, 1999; 19(12): 4839 - 4846. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. W. Paetkau, V. A. Elagin, L. M. Sendi, and D. R. Hyde Isolation and Characterization of Drosophila retinal degeneration B Suppressors Genetics, February 1, 1999; 151(2): 713 - 724. [Abstract] [Full Text] |
||||
![]() |
H. A. Colbert, T. L. Smith, and C. I. Bargmann OSM-9, A Novel Protein with Structural Similarity to Channels, Is Required for Olfaction, Mechanosensation, and Olfactory Adaptation in Caenorhabditis elegans J. Neurosci., November 1, 1997; 17(21): 8259 - 8269. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Montell New Light on TRP and TRPL Mol. Pharmacol., November 1, 1997; 52(5): 755 - 763. [Abstract] [Full Text] |
||||
![]() |
B. Gillo, I. Chorna, H. Cohen, B. Cook, I. Manistersky, M. Chorev, A. Arnon, J. A. Pollock, Z. Selinger, and B. Minke Coexpression of Drosophila TRP and TRP-like proteins in Xenopus oocytes reconstitutes capacitative Ca2+ entry PNAS, November 26, 1996; 93(24): 14146 - 14151. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Huber, P. Sander, and R. Paulsen Phosphorylation of the InaD Gene Product, a Photoreceptor Membrane Protein Required for Recovery of Visual Excitation J. Biol. Chem., May 17, 1996; 271(20): 11710 - 11717. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. C. Hardie INDO-1 Measurements of Absolute Resting and Light-Induced Ca2+ Concentration in Drosophila Photoreceptors J. Neurosci., May 1, 1996; 16(9): 2924 - 2933. [Abstract] [Full Text] [PDF] |
||||
|
|