Report

Role for the Target Enzyme in Deactivation of Photoreceptor G Protein in Vivo

See allHide authors and affiliations

Science  02 Oct 1998:
Vol. 282, Issue 5386, pp. 117-121
DOI: 10.1126/science.282.5386.117

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Heterotrimeric guanosine 5′-triphosphate (GTP)–binding proteins (G proteins) are deactivated by hydrolysis of the GTP that they bind when activated by transmembrane receptors. Transducin, the G protein that relays visual excitation from rhodopsin to the cyclic guanosine 3′,5′-monophosphate phosphodiesterase (PDE) in retinal photoreceptors, must be deactivated for the light response to recover. A point mutation in the γ subunit of PDE impaired transducin-PDE interactions and slowed the recovery rate of the flash response in transgenic mouse rods. These results indicate that the normal deactivation of transducin in vivo requires the G protein to interact with its target enzyme.

  • * These authors contributed equally to this work.

  • To whom correspondence should be addressed. E-mail: varshavsky{at}meei.harvard.edu

View Full Text