Paxillin, a tyrosine phosphorylated focal adhesion-associated protein binds to the carboxyl terminal domain of focal adhesion kinase.
Focal adhesion kinase (pp125FAK or FAK) and paxillin colocalize with integrins in structures called focal adhesions. pp125FAK plays an important role in the transmission of integrin-induced cytoplasmic signals. Paxillin has also been implicated in cell signaling by virtue of its association with the protein tyrosine kinases pp60src and Csk (C-terminal Src kinase) as well as with the adapter/oncoprotein p47gag-crk. In this report we show that endogenous pp125FAK and paxillin form a stable complex both in vivo and in vitro and that this interaction is direct, requiring only pp125FAK and paxillin. The paxillin binding site on pp125FAK has been localized to the carboxy-terminal 148 residues of pp125FAK, but appears to be distinct from the previously identified focal adhesion-targeting sequence also present in the carboxy-terminal domain of pp125FAK. The interaction of paxillin and pp125FAK is independent of the adhesion of cells to the extracellular matrix, as the association can be detected in suspension cells as well as those attached to fibronectin.
Hildebrand
J D
JD
Department of Microbiology, University of Virginia, Charlottesville 22908, USA.
Schaller
M D
MD
Parsons
J T
JT
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism*; D002478:Cells, Cultured; D002642:Chick Embryo; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D000939:Epitopes / Q000276:immunology; D005109:Extracellular Matrix / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015967:Gene Expression Regulation, Viral; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000276:immunology / Q000378:metabolism*; D011972:Receptor, Insulin / Q000276:immunology / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D017384:Sequence Deletion; D013329:Structure-Activity Relationship
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D000939:Epitopes; D051419:Paxillin; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases