Fig. 3

Paxillin structural and functional organization. Human paxillin protein includes 591 amino acids. The N-terminus contains a proline-rich region that anchors SH3-containing proteins and five leucine-rich LD domains (LD1–LD5), which include docking sequences for the recruitment of signaling and structural molecules such as FAK, vinculin, and Crk. The C-terminus contains four cystein-histidine-enriched LIM domains, involved in the anchoring of paxillin to the plasma membrane and its targeting to focal adhesions. Paxillin is phosphorylated in response to cell adhesion and cytokine or growth factor stimulation: Tyrosine phosphorylation generates interaction sites for signaling molecules, which in turn regulate paxillin targeting to FAs. Serine phosphorylation, results in a number of functional modifications involved in the regulation of the adhesion process and cell movement