HCK antibody

Background of HCK antibody

Hck (hemopoietic cell kise) is a protein tyrosine kise of the Src family prominently expressed in the lymphoid and myeloid lineages of hemopoiesis. It participates in transducing a variety of extracellular sigls, which ultimately affect cellular processes including proliferation, differentiation and migration.The well-defined modular structure of Hck comprises a relatively divergent, NH2-termil "unique" domain, which is subject to post-translatiol lipid modifications thereby targeting Hck to the plasma membrane. Src homology 3 (SH3) and 2 (SH2) domains, and a tyrosine kise catalytic domain follow the "unique" domain. The catalytic activity of Hck is regulated, both positively and negatively, by tyrosine phosphorylation of highly conserved tyrosine (Y) residues. Phosphorylation of a single conserved Tyr499 residue in the COOH terminus of Hck by the protein kise Csk renders Hck ictive as a result of an intramolecular interaction between the phosphorylated tyrosine (pY) residue and its own SH2 domain. Disruption of this interaction, either as a result of dephosphorylation, or substitution of the COOH-termil regulatory Y residue with phenylalanine (F; e.g., HckY499F), or COOH-termil truncation mutations as observed in the virally transduced v-Src oncoprotein, results in constitutive activation of Hck. In contrast to phosphorylation of the COOH-termil regulatory tyrosine residue, autophosphorylation of a tyrosine residue (Tyr388) within the kise domain of Hck acts to positively regulate its catalytic activity. Thus, activation of Hck requires both disruption of the COOH-termil regulatory tyrosine-SH2 domain interaction and autophosphorylation of the regulatory tyrosine residue within the kise domain. The dysfunction or dysregulation of Hck may contribute to the pathogenesis of some human leukemias.