Description
Lymphocyte specific protein tyrosine kinase (LCK) belongs to Src family protein-tyrosine kinase. It is essential for T-cell development and function. The activity p56lckis regulated by phosphorylation and dephosphorylation of two critical tyrosine residues Tyr394 and Tyr505. Tyr394 and Tyr505 are autophosphorylated after p56lck activation, whereas phosphorylation of Tyr505 is believed to be due to p50csk which negatively modulates P56lck activity. Autophosphorylation at Tyr505 of P56lck may represent an accessory mechanism for the down-regulation of the tyrosine kinase activity of P56lck