|
 |
|
|
| Subject Categories: Cell & Tissue Architecture | Signal Transduction |
|
| The EMBO Journal
(2003) 22, 459–468, doi:10.1093/emboj/cdg054 |
|
Regulation of light-dependent Gq translocation and morphological changes in fly photoreceptors |
|
|
| Mickey Kosloff1, 4, Natalie Elia1, 4, Tamar Joel-Almagor2, Rina Timberg1, Troy D. Zars3, David R. Hyde3, Baruch Minke2 and Zvi Selinger1 |
|
|
1 Department of Biological Chemistry and the Kühne Minerva Center for Studies of Visual Transduction, Institute of Life Sciences, The Hebrew University, Givat Ram, Jerusalem, 91904, Israel 2 Department of Physiology and the Kühne Minerva Center for Studies of Visual Transduction, The Hebrew University, Jerusalem, 91120, Israel 3 Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-0369, USA 4 M.Kosloff and N.Elia contributed equally to this work To whom correspondence should be addressed Zvi Selinger, selinger@vms.huji.ac.il Received 8 May 2002; Revised 21 November 2002; Accepted 3 December 2002. |
|
|
|
| Abstract |
|
Heterotrimeric G-proteins relay signals between membrane-bound receptors and downstream effectors. Little is known, however, about the regulation of G subunit localization within the natural endogenous environment of a specialized signaling cell. Here we show, using live Drosophila flies, that light causes massive and reversible translocation of the visual Gq to the cytosol, associated with marked architectural changes in the signaling compartment. Molecular genetic dissection together with detailed kinetic analysis enabled us to characterize the translocation cycle and to unravel how signaling molecules that interact with Gq affect these processes. Epistatic analysis showed that Gq is necessary but not sufficient to bring about the morphological changes in the signaling organelle. Furthermore, mutant analysis indicated that Gq is essential for targeting of Gq to the membrane and suggested that Gq is also needed for efficient activation of Gq by rhodopsin. Our results support the 'two-signal model' hypothesis for membrane targeting in a living organism and characterize the regulation of both the activity-dependent Gq localization and the cellular architectural changes in Drosophila photoreceptors. |
|
| Keywords: G-protein, localization, membrane attachment, rhabdomere, vision |
|
|
| |
| |
| |
 | Email link to a friend |
| |
 | Download PDF |
| |
 | Full text |
| |
| |
| |
 | Next article |
| |
 | Previous article |
| |
 | Table of contents |
| |
| |
 | Rights and permissions |
| |
 | Reprints |
| |
| |
| |
 Register for table of contents by email | |
| |
| |
| |