c-Kit is a member of the subfamily of receptor tyrosine kinases that includes PDGF, CSF-1 and FLT3/flk-2 receptors. It plays critical controlling roles in a number of cell types such as hematopoietic stem cells, mast cells, melanocytes and germ cells. Upon binding with its ligand, stem cell factor (SCF), c-Kit undergoes dimerization/oligomerization and autophosphorylation. Activation of c-Kit results in the recruitment and tyrosine phosphorylation of downstream SH2-containing signaling components including PLCg, the p85 subunit of PI3 kinase, SHP2 and CrkL. Molecular lesions that impair the kinase activity of c-Kit are associated with a variety of developmental disorders, while mutations that constitutively activate c-Kit can lead to pathogenesis of mastocytosis and gastrointestinal stromal tumors. Tyr719 is located in the kinase insert region of the catalytic domain. c-Kit phosphorylated at Tyr719 binds to the p85 subunit of PI3 kinase in vitro and in vivo. c-Kit D816V, a constitutively active Kit mutant, has been found in adult-type human mastocytosis and is resistant to Gleevec (Imatinib), which has been successfully used to treat c-Kit kinase associated chronic myeloid leukemia (CML). Source: Human cKit (D816V), aa544-end, with N-terminal His tag, expressed in an Baculovirus infected Sf9 cell expression system. Molecular Weight: 50kD Specific Activity: 152pmol/min/mg Application: Useful for the study of enzyme kinetics, screening inhibitors, and selectivity profiling. Other applications not tested. Reaction Buffer: 50mM HEPES, pH7.5, 10mM MgCl2, 1mM EGTA, 200uM ATP, 0.01% Brij-35 and 2uM substrate (Tyr Peptide 6, Invitrogen) at room temperature for 1 hour. Storage and Stability: Aliquot to avoid repeated freezing and thawing and store at -70C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Aliquots are stable for at least 6 months.
