Publication Date:
1997-01-17
Description:
Transmembrane receptors for hormones, neurotransmitters, light, and odorants mediate their cellular effects by activating heterotrimeric guanine nucleotide-binding proteins (G proteins). Crystal structures have revealed contact surfaces between G protein subunits, but not the surfaces or molecular mechanism through which Galphabetagamma responds to activation by transmembrane receptors. Such a surface was identified from the results of testing 100 mutant alpha subunits of the retinal G protein transducin for their ability to interact with rhodopsin. Sites at which alanine substitutions impaired this interaction mapped to two distinct Galpha surfaces: a betagamma-binding surface and a putative receptor-interacting surface. On the basis of these results a mechanism for receptor-catalyzed exchange of guanosine diphosphate for guanosine triphosphate is proposed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Onrust, R -- Herzmark, P -- Chi, P -- Garcia, P D -- Lichtarge, O -- Kingsley, C -- Bourne, H R -- CA-54427/CA/NCI NIH HHS/ -- GM-27800/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Jan 17;275(5298):381-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94143-0450, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/8994033" target="_blank"〉PubMed〈/a〉
Keywords:
Aluminum Compounds/pharmacology
;
Animals
;
Binding Sites
;
COS Cells
;
Fluorides/pharmacology
;
Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
;
Guanosine Diphosphate/metabolism
;
Models, Molecular
;
Mutation
;
Phenotype
;
*Protein Conformation
;
Retinaldehyde/pharmacology
;
Rhodopsin/*metabolism/pharmacology
;
Rod Cell Outer Segment/metabolism
;
Transducin/*chemistry/metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
