Phospho-Paxillin (Tyr118) Recombinant Rabbit mAb (S-4990)

Phospho-Paxillin (Tyr118) refers to the phosphorylated form of paxillin at tyrosine residue 118, serving as a key activation marker of cell adhesion, cytoskeletal reorganization, and signal transduction. Paxillin is a multi-domain adaptor protein localized to focal adhesions, and its Tyr118 site can be phosphorylated by non-receptor tyrosine kinases such as FAK (focal adhesion kinase) and Src family kinases. This phosphorylation event provides a high-affinity binding site for SH2 domain-containing effector proteins (e.g., Crk, Dock180), subsequently activating small GTPases such as Rac1 and Cdc42 to regulate cell migration, invasion, and survival. Following cell adhesion to the extracellular matrix, integrin-mediated FAK activation rapidly upregulates p-Paxillin (Tyr118) levels, promoting focal adhesion dynamics and protrusion formation; conversely, its phosphorylation level decreases significantly during cell detachment or under stress conditions. This modification is particularly critical in tumor invasion and metastasis, as high expression of p-Paxillin (Tyr118) is closely associated with the metastatic potential and poor prognosis of various solid tumors, including breast cancer and colorectal cancer. Additionally, p-Paxillin (Tyr118) participates in physiological processes such as neuronal axon guidance, regulation of cardiomyocyte contractile function, and wound healing, and is often used as a biomarker to assess cell migration activity and evaluate drug efficacy targeting the focal adhesion kinase signaling pathway.