Paxillin (Thr-538), Phosphospecific Antibody

Paxillin, a focal adhesion protein, is involved in focal adhesion formation during cell adhesion and migration. Paxillin contains LD motifs, LIM domains, and SH3-/SH2-binding domains that participate in a variety of protein-protein interactions with kinases, GTPase-activating proteins, and cytoskeletal proteins. Phosphorylation of paxillin occurs at tyrosine, threonine, and serine sites. Serine and threonine phosphorylation of paxillin occur in response to growth-factor activation, PKC activators, and fibronectins. Phosphorylation of Ser-85, Ser-178, and Thr-538 may be important sites for regulating paxillin activity. Paxillin phosphorylation of Thr-538 occurs in response to TPA-activated PKCs in vitro, and this phosphorylation may contribute to dissolution of the actin cytoskeleton and redistribution of LFA-1 integrins in vivo.

This antibody detects a 68kDa* protein corresponding to the molecular mass of paxillin on SDS-PAGE immunoblots of A431 cells treated with calyculin A. This reactivity is not observed after lambda phosphatase treatment. This sequence is highly conserved in rat and mouse paxillin and is also found in the other paxillin isoforms (b & g) .