Paxillin (Pax)

Paxillin is a signal transduction adaptor protein and should not be confused with the neurotoxin paxilline.Glenney and Zokas (1989) used an antiphosphotyrosine antibody to identify proteins that are phosphorylated in Rous sarcoma virus-transformed chick embryo fibroblasts, and found a 76-kD protein that localizes to focal adhesions at the ends of actin-containing stress fibers in nontransformed cells. Turner et al. (1990) purified this protein from chicken gizzard smooth muscle, and named it paxillin ("""paxillus""" means """small stake""" or """peg""" in Latin) as a protein tethered to the membrane at focal adhesions.Paxillin migrates as a diffuse 65- to 70-kD band on SDS-PAGE. Salgia et al. (1995) stated that transmembrane integrin molecules connect the actin cytoskeleton to the extracellular matrix within focal adhesions.