Journal article
Diffusion and light-dependent compartmentalization of transducin
Molecular and cellular neurosciences, Vol.46(1), pp.340-346
01/2011
DOI: 10.1016/j.mcn.2010.10.006
PMCID: PMC3018668
PMID: 21044685
Abstract
Diffusion and light-dependent compartmentalization of transducin are essential for phototransduction and light adaptation of rod photoreceptors. Here, transgenic Xenopus laevis models were designed to probe the roles of transducin/rhodopsin interactions and lipid modifications in transducin compartmentalization, membrane mobility, and light-induced translocation. Localization and diffusion of EGFP-fused rod transducin-α subunit (Gα(t1)), mutant Gα(t1) that is predicted to be N-acylated and S-palmitoylated (Gα(t1)A3C), and mutant Gα(t1) uncoupled from light-activated rhodopsin (Gα(t1)-Ctα(s)), were examined by EGFP-fluorescence imaging and fluorescence recovery after photobleaching (FRAP). Similar to Gα(t1), Gα(t1)A3C and Gα(t1)-Ctα(s) were correctly targeted to the rod outer segments in the dark, however the light-dependent translocation of both mutants was markedly impaired. Our analysis revealed a moderate acceleration of the lateral diffusion for the activated Gα(t1) consistent with the diffusion of the separated Gα(t1)GTP and Gβ(1)γ(1) on the membrane surface. Unexpectedly, the kinetics of longitudinal diffusion were comparable for Gα(t1)GTP with a single lipid anchor and heterotrimeric Gα(t1)β(1)γ(1) or Gα(t1)-Ctα(s)β(1)γ(1) with two lipid modifications. This contrasted the lack of the longitudinal diffusion of the Gα(t1)A3C mutant apparently caused by its stable two lipid attachment to the membrane and suggests the existence of a mechanism that facilitates axial diffusion of Gα(t1)β(1)γ(1).
Details
- Title: Subtitle
- Diffusion and light-dependent compartmentalization of transducin
- Creators
- Vasily Kerov - Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA 52242, USANikolai O Artemyev
- Resource Type
- Journal article
- Publication Details
- Molecular and cellular neurosciences, Vol.46(1), pp.340-346
- DOI
- 10.1016/j.mcn.2010.10.006
- PMID
- 21044685
- PMCID
- PMC3018668
- NLM abbreviation
- Mol Cell Neurosci
- ISSN
- 1044-7431
- eISSN
- 1095-9327
- Publisher
- United States
- Grant note
- R01 EY-12682 / NEI NIH HHS R01 EY012682 / NEI NIH HHS R01 EY012682-12 / NEI NIH HHS
- Language
- English
- Date published
- 01/2011
- Academic Unit
- Molecular Physiology and Biophysics; Iowa Neuroscience Institute; Ophthalmology and Visual Sciences
- Record Identifier
- 9984025319602771
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