The long term goal of the research is to study the fundamental molecular, cell biology and physiological mechanisms underlying retinal degeneration and long-term adaptation through studies aiming to elucidate the mechanisms of activation, inactivation and translocation of signaling molecules. These molecules include the Gq, Dmoesin and the light activated channels TRP and TRPL, which cause cell death upon malfunction.
Our specific aims are: i) To explore the molecular mechanism underlying the activation of the TRP and TRPL channels by metabolic stress in the dark, by studying the synergistic effects of cytosolic Ca2+ and protein phosphorylation and dephosphorylation reactions on TRP and TRPL activation and gating mechanism. Transgenic Drosophila lacking putative phosphorylation sites will be generated and studied, as well as transgenic Drosophila lacking or over expressing protein kinases and protein phosphatases. ii) To apply structure-function analysis of the TRP and TRPL channels. Site-directed mutations in TRP and TRPL channels will be generated. The mutant channels will be heterologously expressed in a stable form in Schneider, S2, cells together with the main proteins of the INAD signaling complex (INAD scaffold protein, PLC and PKC). The heterologous expression will be followed by a step by step comparison of the effects of critical mutations in the TRP and TRPL channels expressed in S2 cells to the same mutations in the native system using transgenic flies, in vivo, iii) To study the mechanisms underlying light-induced translocation of Gqa and TRPL and their functional consequences. We will investigate the effect of Gqa translocation on long-term light adaptation. Furthermore, we will investigate the molecular mechanism underlying retinal degeneration induced by abnormal localization of active Gqa in the cytosol of the rhodopsin mutant ninaEPPlOO. We will, furthermore, test the hypothesis that light and phosphorylation-dependent translocation of the cytoskeletal protein, Dmoesin out of the rhabdomere triggers TRPL translocation, which induces long term adaptation. This study is thus expected to shed new light on major unsolved questions of TRP gating, which is involved in several diseases and on light induced translocation of key signaling molecules.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY003529-28
Application #
7484154
Study Section
Biophysics of Synapses, Channels, and Transporters Study Section (BSCT)
Program Officer
Mariani, Andrew P
Project Start
1981-09-01
Project End
2009-08-31
Budget Start
2008-09-01
Budget End
2009-08-31
Support Year
28
Fiscal Year
2008
Total Cost
$154,162
Indirect Cost
Name
Hebrew University of Jerusalem
Department
Type
DUNS #
600044978
City
Jerusalem
State
Country
Israel
Zip Code
91904
Voolstra, Olaf; Rhodes-Mordov, Elisheva; Katz, Ben et al. (2017) The Phosphorylation State of the Drosophila TRP Channel Modulates the Frequency Response to Oscillating Light In Vivo. J Neurosci 37:4213-4224
Weiss, Shirley; Minke, Baruch (2015) A new genetic model for calcium induced autophagy and ER-stress in Drosophila photoreceptor cells. Channels (Austin) 9:14-20
Kohn, Elkana; Katz, Ben; Yasin, Bushra et al. (2015) Functional cooperation between the IP3 receptor and phospholipase C secures the high sensitivity to light of Drosophila photoreceptors in vivo. J Neurosci 35:2530-46
Katz, Ben; Oberacker, Tina; Richter, David et al. (2013) Drosophila TRP and TRPL are assembled as homomultimeric channels in vivo. J Cell Sci 126:3121-33
Lev, Shaya; Katz, Ben; Tzarfaty, Vered et al. (2012) Signal-dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate without activation of phospholipase C: implications on gating of Drosophila TRPL (transient receptor potential-like) channel. J Biol Chem 287:1436-47
Lev, Shaya; Katz, Ben; Minke, Baruch (2012) The activity of the TRP-like channel depends on its expression system. Channels (Austin) 6:86-93
Katz, Ben; Minke, Baruch (2012) Phospholipase C-mediated suppression of dark noise enables single-photon detection in Drosophila photoreceptors. J Neurosci 32:2722-33
Weiss, Shirley; Kohn, Elkana; Dadon, Daniela et al. (2012) Compartmentalization and Ca2+ buffering are essential for prevention of light-induced retinal degeneration. J Neurosci 32:14696-708
Richter, David; Katz, Ben; Oberacker, Tina et al. (2011) Translocation of the Drosophila transient receptor potential-like (TRPL) channel requires both the N- and C-terminal regions together with sustained Ca2+ entry. J Biol Chem 286:34234-43
Minke, Baruch (2010) The history of the Drosophila TRP channel: the birth of a new channel superfamily. J Neurogenet 24:216-33

Showing the most recent 10 out of 80 publications