Pugh Edward N
F. M. Kirby Center for Molecular Ophthalmology, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, 19104, USA.
Neuron. 2006 Aug 17;51(4):391-3. doi: 10.1016/j.neuron.2006.08.002.
Regulators of G protein signaling (RGS) constitute a family of proteins that bind specifically to the activated alpha subunits of G proteins (Galpha-GTP), acting as GTPase activating proteins, or GAPs, for the rate of GTP hydrolysis. In this issue of Neuron, Krispel et al. resolve a long-standing puzzle in phototransduction, establishing that RGS9 "GAPping" of G(t)alpha-GTP is the molecular mechanism underlying the dominant recovery time constant of mouse rod photoreceptors and that a precise level of expression of RGS9 is required for normal photoresponse timing.
G蛋白信号调节因子（RGS）构成了一类蛋白质家族，它们能特异性地结合G蛋白的活化α亚基（Gα-GTP），作为GTP酶激活蛋白（GAPs）来调节GTP水解的速率。在本期《神经元》杂志中，克里斯佩尔等人解开了光转导领域一个长期存在的谜题，证实G（t）α-GTP的RGS9“GAP作用”是小鼠视杆光感受器主要恢复时间常数的分子机制，并且正常的光反应计时需要精确水平的RGS9表达。
