title: Src-mediated caveolin-1 phosphorylation affects the targeting of active Src to specific membrane sites.
abstract: Src interactions with the plasma membrane are an important determinant of its activity. In turn, Src activity modulates its association with the membrane through binding of activated Src to phosphotyrosylated proteins. Caveolin-1 (Cav-1), a major component of caveolae, is a known Src phosphorylation target, and both were reported to regulate cell transformation. However, the nature of Src-Cav-1 interactions, a potential mechanism of their coregulation, remained unclear. Here we used fluorescence recovery after photobleaching beam-size analysis, coimmunoprecipitation, quantitative imaging, and far-Western studies with cells expressing wild type, as well as structural and activity mutants of Src-green fluorescent protein and Cav-1-monomeric red fluorescent protein, to measure their interactions with the membrane and with each other. We show dynamic Src-plasma membrane interactions, which are augmented and stabilized by Cav-1. The mechanism involves phosphorylation of Cav-1 at Tyr-14 by Src and subsequent binding of the Src SH2 domain to phospho-Cav-1, leading to accumulation of activated Src in focal adhesions. This novel Cav-1 function potentially modulates focal adhesion dynamics.
authors.affiliation: Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720.
authors.forename: Efrat
authors.initials: E
authors.lastname: Gottlieb-Abraham
authors.forename: Dmitry E
authors.initials: DE
authors.lastname: Shvartsman
authors.forename: John C
authors.initials: JC
authors.lastname: Donaldson
authors.forename: Marcelo
authors.initials: M
authors.lastname: Ehrlich
authors.forename: Orit
authors.initials: O
authors.lastname: Gutman
authors.forename: G Steven
authors.initials: GS
authors.lastname: Martin
authors.forename: Yoav I
authors.initials: YI
authors.lastname: Henis
mesh_terms: D000818:Animals; D019556:COS Cells; D051242:Caveolin 1 / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002522:Chlorocebus aethiops; D002784:Cholesterol / Q000096:biosynthesis; D022001:Focal Adhesions; D049452:Green Fluorescent Proteins / Q000235:genetics; D008164:Luminescent Proteins / Q000235:genetics; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D034741:RNA, Small Interfering; D051381:Rats; D019061:src-Family Kinases / Q000378:metabolism*; D000097573:Red Fluorescent Protein
chemical_list: D051242:Caveolin 1; D002784:Cholesterol; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D034741:RNA, Small Interfering; D019061:src-Family Kinases; D000097573:Red Fluorescent Protein; C495537:Cav1 protein, rat