RGS expression level precisely regulates the duration of rod photoresponses.
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.
Pugh
Edward N
EN
F. M. Kirby Center for Molecular Ophthalmology, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, 19104, USA.
D000818:Animals; D015870:Gene Expression / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D020710:RGS Proteins / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D014785:Vision, Ocular / Q000502:physiology*
D020710:RGS Proteins; D006160:Guanosine Triphosphate