title: Identification of a novel protein complex containing annexin VI, Fyn, Pyk2, and the p120(GAP) C2 domain.
abstract: p120(GAP) (RasGAP) has been proposed to function as both an inhibitor and effector of Ras. Previously we have shown that RasGAP contains a C2 domain which mediates both Ca(2+)-dependent membrane association and protein-protein interactions. Specifically, three proteins have been isolated in a complex with the C2 domain of RasGAP; these are the Ca(2+)-dependent lipid binding protein annexin VI (p70) and two previously unidentified proteins, p55 and p120. Here we provide evidence that p55 is the Src family kinase Fyn and p120 is the focal adhesion kinase family member Pyk2. In addition, in vitro binding assays indicate that Fyn, but not Pyk2 binds directly to annexin VI. Finally, co-immunoprecipitation studies in Rat-1 fibroblasts confirm that Fyn, Pyk2, annexin VI and RasGAP can form a protein complex in mammalian cells.
authors.affiliation: School of Biomedical Sciences, University of Leeds, Woodhouse Lane, Leeds, UK.
authors.forename: A
authors.initials: A
authors.lastname: Chow
authors.forename: A J
authors.initials: AJ
authors.lastname: Davis
authors.forename: D J
authors.initials: DJ
authors.lastname: Gawler
mesh_terms: D000818:Animals; D017317:Annexin A6 / Q000378:metabolism*; D002478:Cells, Cultured; D051418:Focal Adhesion Kinase 2; D009097:Multienzyme Complexes / Q000737:chemistry / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051076:Proto-Oncogene Proteins c-fyn; D051381:Rats; D012756:Sheep; D015398:Signal Transduction; D014162:Transfection; D020729:p120 GTPase Activating Protein / Q000378:metabolism*
chemical_list: D017317:Annexin A6; D009097:Multienzyme Complexes; D011518:Proto-Oncogene Proteins; D020729:p120 GTPase Activating Protein; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; C494961:Fyn protein, rat; D051076:Proto-Oncogene Proteins c-fyn; C496054:Ptk2b protein, rat