Conformational activation of radixin by G13 protein alpha subunit.
G(13) protein, one of the heterotrimeric guanine nucleotide-binding proteins (G proteins), regulates diverse and complex cellular responses by transducing signals from the cell surface presumably involving more than one pathway. Yeast two-hybrid screening of a mouse brain cDNA library identified radixin, a member of the ERM family of three closely related proteins (ezrin, radixin, and moesin), as a protein that interacted with Galpha(13). Interaction between radixin and Galpha(13) was confirmed by in vitro binding assay and by co-immunoprecipitation technique. Activated Galpha(13) induced conformational activation of radixin, as determined by binding of radixin to polymerized F-actin and by immunofluorescence in intact cells. Finally, two dominant negative mutants of radixin inhibited Galpha(13)-induced focus formation of Rat-1 fibroblasts but did not affect Ras-induced focus formation. Our results identifying a new signaling pathway for Galpha(13) indicate that ERM proteins can be activated by and serve as effectors of heterotrimeric G proteins.
Vaiskunaite
R
R
Department of Pharmacology, University of Illinois, Chicago, Illinois 60612, USA.
Adarichev
V
V
Furthmayr
H
H
Kozasa
T
T
Gudkov
A
A
Voyno-Yasenetskaya
T A
TA
D016475:3T3 Cells; D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D015398:Signal Transduction; D015003:Yeasts; D000099149:Ezrin
D001798:Blood Proteins; D003598:Cytoskeletal Proteins; D044365:GTP-Binding Protein alpha Subunits, G12-G13; D020962:Heterotrimeric GTP-Binding Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; D000099149:Ezrin; C071058:moesin; C071776:radixin