Direct association of pp125FAK with paxillin, the focal adhesion-targeting mechanism of pp125FAK.
Focal adhesion kinase (pp125FAK) is localized to focal adhesions and tyrosine phosphorylated by the engagement of beta 1 integrins. However, it is unclear how pp125FAK is linked to integrin molecules. We demonstrate that pp125FAK is directly associated with paxillin, a 68-kD cytoskeleton protein. The COOH-terminal domain of pp125FAK spanning FAK residues 919-1042 is sufficient for paxillin binding and has vinculin-homologous amino acids, which are essential for paxillin binding. Microinjection and subsequent immunohistochemical analysis reveal that glutathione S-transferase-FAK fusion proteins, which bind to paxillin, localize to focal adhesions, whereas fusion proteins with no paxillin-binding activity do not localize to focal adhesions. These findings strongly suggest that pp125FAK is localized to focal adhesions by the direct association with paxillin.
Tachibana
K
K
Division of Tumor Immunology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.
Sato
T
T
D'Avirro
N
N
Morimoto
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D051419:Paxillin; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D016596:Vinculin / Q000235:genetics
D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; C496062:Pxn protein, mouse; D016596:Vinculin; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; C496051:Ptk2 protein, mouse