Paxillin: a new vinculin-binding protein present in focal adhesions.

Abstract

Abstract. The 68-kD protein (paxillin) is a cytoskeletal component that localizes to the focal adhesions at the ends of actin stress fibers in chicken embryo fibroblasts. It is also present in the focal adhesions of Madin-Darby bovine kidney (MDBK) epithelial cells but is absent, like talin, from the cell-cell adherens junctions of these cells. Paxillin purified from chicken gizzard smooth muscle migrates as a diffuse band on SDS-PAGE gels with a molecular mass of 65-70 kD. It is a protein of multiple isoforms with pls ranging from 6.31 to 6.85. Using purified paxillin, we have demonstrated a specific interaction in vitro with another focal adhesion protein, vinculin. Cleavage of vinculin with Staphylococcus aureus V8 protease results in the generation of two fragments of ~85 and 27 kD. Unlike talin, which binds to the large vinculin fragment, paxillin was found to bind to the small vinculin fragment, which represents the rod domain of the molecule. Together with the previous observation that paxillin is a major substrate of pp60 src in Rous sarcoma virus-transformed ceils (Glenney, J. R., and L.

Serine phosphorylation of paxillin by heregulin-β1: role of p38 mitogen activated protein kinase

“…In contrast to the earlier reports, we have now demonstrated, for the ®rst time, the potential involvement of serine phosphorylation of paxillin during HRG-induced cell shape changes. The migration of paxillin as a di use band with slower mobility has been shown to be associated with serine/threonine phosphorylation (Turner et al, 1990). Data from the literature suggest that paxillin can be phosphorylated on serine residues in response to cell adhesion to ®bronectin (Bellis et al, 1997) and vitronectin (De Nichilo and Yamada, 1996).…”

SLK-mediated phosphorylation of paxillin is required for focal adhesion turnover and cell migration

“…Paxillin first gained widespread interest in 1990 when it was shown not only to localize to integrin-rich sites of focal adhesions, but to also be a novel binding partner for the focal adhesion and actin-binding protein, vinculin [66,83]. The name paxillin, derived from the latin 'paxillus' meaning small stake or peg, was chosen to describe this protein in accordance with its ability to tether proteins like vinculin, to the membrane at focal adhesions [66,84].…”

Scaffold mediated regulation of MAPK signaling and cytoskeletal dynamics: A perspective

“…Focal adhesions contain more than fifty proteins, many of which are tyrosine phosphorylated and/or themselves tyrosine kinases. Tyrosine phosphorylation at adhesion sites occurs after the initial recruitment of talin and paxillin apparently followed by FAK and vinculin to focal sites [74][75][76][77]. Tensin and zyxin are generally absent from nascent adhesions [74].…”