Src

This monoclonal antibody recognizes a 60 kDa protein identified as Src. Src (also known as pp60src) is a non-receptor tyrosine kinase involved in signal transduction in many biological systems and implicated in the development of human tumors. There are two critical phosphorylation sites of tyrosine on Src, tyrosine 418 and tyrosine 529 (referring to human Src sequence). The tyrosine 418 is located in the catalytic domain and is one of the autophosphorylation sites. Full catalytic activity of Src requires phosphorylation of tyrosine 418. The tyrosine 529 is located near the carboxyl terminus of Src and acts as a negative regulator, in that Src is held in the inactive form through an intramolecular interaction between the SH2 domain and the carboxyl terminus when tyrosine 529 is phosphorylated by Csk. This conformation blocks phosphorylation of tyrosine 418 at the catalytic domain, thereby preventing Src activation. When tyrosine 529 is dephosphorylated, tyrosine 418 can be maximally phosphorylated and Src becomes active.