Transducin Activation State Controls Its Light-dependent Translocation in Rod Photoreceptors

Vasily Kerov; Desheng Chen; Mustapha Moussaif; Yu-Jiun Chen; Ching-Kang Chen; Nikolai O Artemyev

doi:10.1074/jbc.M508849200

Back

Transducin Activation State Controls Its Light-dependent Translocation in Rod Photoreceptors

Journal article

Open access

Peer reviewed

Transducin Activation State Controls Its Light-dependent Translocation in Rod Photoreceptors

Vasily Kerov, Desheng Chen, Mustapha Moussaif, Yu-Jiun Chen, Ching-Kang Chen and Nikolai O Artemyev

The Journal of biological chemistry, Vol.280(49), pp.41069-41076

12/09/2005

DOI: 10.1074/jbc.M508849200

PMID: 16207703

Files and links (1)

url

https://doi.org/10.1074/jbc.M508849200View

Published (Version of record) Open Access

Abstract

Light-dependent redistribution of transducin between the rod outer segments (OS) and other photoreceptor compartments including the inner segments (IS) and synaptic terminals (ST) is recognized as a critical contributing factor to light and dark adaptation. The mechanisms of light-induced transducin translocation to the IS/ST and its return to the OS during dark adaptation are not well understood. We have probed these mechanisms by examining light-dependent localizations of the transducin-α subunit (Gtα)in mice lacking the photoreceptor GAP-protein RGS9, or expressing the GTPase-deficient mutant GtαQ200L. An illumination threshold for the Gtα movement out of the OS is lower in the RGS9 knockout mice, indicating that the fast inactivation of transducin in the wild-type mice limits its translocation to the IS/ST. Transgenic GtαQ200L mice have significantly diminished levels of proteins involved in cGMP metabolism in rods, most notably the PDE6 catalytic subunits, and severely reduced sensitivity to light. Similarly to the native Gtα, the GtαQ200L mutant is localized to the IS/ST compartment in light-adapted transgenic mice. However, the return of GtαQ200L to the OS during dark adaptation is markedly slower than normal. Thus, the light-dependent translocations of transducin are controlled by the GTP-hydrolysis on Gtα, and apparently, do not require Gtα interaction with RGS9 and PDE6.

Details

Title: Subtitle: Transducin Activation State Controls Its Light-dependent Translocation in Rod Photoreceptors
Creators: Vasily Kerov - Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242
Desheng Chen - Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298
Mustapha Moussaif - Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242
Yu-Jiun Chen - Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298
Ching-Kang Chen - Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298
Nikolai O Artemyev - Department of Physiology and Biophysics, University of Iowa College of Medicine, Iowa City, Iowa 52242
Resource Type: Journal article
Publication Details: The Journal of biological chemistry, Vol.280(49), pp.41069-41076
DOI: 10.1074/jbc.M508849200
PMID: 16207703
NLM abbreviation: J Biol Chem
ISSN: 0021-9258
eISSN: 1083-351X
Publisher: Elsevier Inc
Language: English
Date published: 12/09/2005
Academic Unit: Molecular Physiology and Biophysics; Iowa Neuroscience Institute; Ophthalmology and Visual Sciences
Record Identifier: 9984070450802771

Metrics

19 Record Views

48 Times Cited - Web of Science