Absence of the RGS9·Gβ5 GTPase-activating Complex in Photoreceptors of the R9AP Knockout Mouse
| Autor: | Peter J. Yoo, Kirill A. Martemyanov, C.M. Krispel, Marie E. Burns, Vadim Y. Arshavsky, Stéphane F. Maison, Stefan Heller, Gabor Keresztes, Hideki Mutai |
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| Rok vydání: | 2004 |
| Předmět: |
genetic structures
Protein family G protein GTPase Biology Biochemistry GTP Phosphohydrolases Mice Regulator of G protein signaling Retinal Rod Photoreceptor Cells RGS9 Animals Molecular Biology Mice Knockout GTP-Binding Protein beta Subunits Membrane Proteins Cell Biology Molecular biology Transmembrane protein Cell biology Enzyme Activation Knockout mouse sense organs Transducin RGS Proteins Photoreceptor Cells Vertebrate |
| Zdroj: | Journal of Biological Chemistry. 279:1581-1584 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.c300456200 |
| Popis: | Timely termination of the light response in retinal photoreceptors requires rapid inactivation of the G protein transducin. This is achieved through the stimulation of transducin GTPase activity by the complex of the ninth member of the regulator of G protein signaling protein family (RGS9) with type 5 G protein beta subunit (Gbeta5). RGS9.Gbeta5 is anchored to photoreceptor disc membranes by the transmembrane protein, R9AP. In this study, we analyzed visual signaling in the rods of R9AP knockout mice. We found that light responses from R9AP knockout rods were very slow to recover and were indistinguishable from those of RGS9 or Gbeta5 knockout rods. This effect was a consequence of the complete absence of any detectable RGS9 from the retinas of R9AP knockout mice. On the other hand, the level of RGS9 mRNA was not affected by the knockout. These data indicate that in photoreceptors R9AP determines the stability of the RGS9.Gbeta5 complex, and therefore all three proteins, RGS9, Gbeta5 , and R9AP, are obligate members of the regulatory complex that speeds the rate at which transducin hydrolyzes GTP. |
| Databáze: | OpenAIRE |
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