Linked Life Data

11882295

Source:http://linkedlifedata.com/resource/pubmed/id/11882295

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-3-7
pubmed:abstractText
Many lines of evidence show that membranes contain microdomains, "lipid rafts", that are different from the rest of the membrane in specific lipid and protein composition. In several biological systems, they were shown to be necessary for trafficking and signal transduction. Here, we investigate if lipid rafts have a role in the regulation of the G protein-mediated pathway underlying vertebrate phototransduction. Photoreceptor membranes contain detergent-resistant membrane (DRM) rafts. Rhodopsin and cGMP phosphodiesterase are found in raft and nonraft portions of the membrane; guanylate cyclase is found exclusively in the raft. Distribution of these proteins does not change in the light or dark. In contrast, the G protein transducin, the RGS9-1-Gbeta5L complex, and the p44 isoform of arrestin undergo dramatic translocation to the raft upon illumination. Phosphorylation of RGS9-1 occurs exclusively in the raft. GTPgammaS or pertussis toxin prevent the light-mediated translocation of transducin and RGS9-1, whereas AlF(minus sign)(4) causes both proteins to move to the raft in the dark. This shows that the Galphat-RGS9-1-Gbeta5L complex has the highest affinity to rafts in the transition state of the GTPase. GTPgammaS binds to transducin at a significantly slower rate in the raft, indicating that this translocation results in a reduced rhodopsin-transducin coupling. Thus, an external signal can rearrange components of a G protein pathway in specific domains of the cell membrane, changing its signaling properties. These findings could reveal a novel mechanism utilized by the cells for regulation of G protein-mediated signal transduction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0960-9822
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
12
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
421-5
pubmed:dateRevised
2011-9-22
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Signal-dependent translocation of transducin, RGS9-1-Gbeta5L complex, and arrestin to detergent-resistant membrane rafts in photoreceptors.
pubmed:affiliation
Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Miami, FL 33136, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't