THE DROSOPHILA DGQ GENE ENCODES A G(ALPHA)-PROTEIN THAT MEDIATES PHOTOTRANSDUCTION
THE DROSOPHILA DGQ GENE ENCODES A G(ALPHA)-PROTEIN THAT MEDIATES PHOTOTRANSDUCTION
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DOI：
10.1016/0896-6273(94)90052-3
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发表时间：
1994-11-01
期刊：
影响因子：
16.2
通讯作者：
HYDE, DR
中科院分区：
文献类型：
--
作者：
LEE, YJ;SHAH, S;HYDE, DR
We examined the roles of the Drosophila G(q alpha) proteins (DG(q)) in the phototransduction pathway. The DG(q) proteins immunolocalized to the ocelli and all eight retinular photoreceptor cell rhabdomeres. An affinity-purified anti-DG(q alpha) immunoglobulin blocked the light-dependent GTP hydrolysis activity associated with Drosophila head membranes in vitro, suggesting that rhodopsin stimulated DG(q). Dominantly active DG(q1) mutants exhibited a light-independent GTPase activity and abnormal electrophysiological light responses, such as reduced retinal sensitivity and slow response kinetics compared with wild-type flies. Dominant DG(q2) mutants exhibited a light-independent GTPase activity with normal electrophysiological light responses. Retinas of double mutants of DG(q1), but not DG(q2), with the light-dependent retinal degeneration mutant rdgB degenerated even in the dark. DG(q1) stimulation of rdgB retinal degeneration in the dark was norpA-dependent. These results indicate that DG(q1) mediates the stimulation by light-activated rhodopsin of the norpA-encoded phospholipase C in the visual transduction cascade.
