Application Methods: IHC-Leica® Bond™, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting
Background: c-Kit is a member of the subfamily of receptor tyrosine kinases that includes PDGF, CSF-1, and FLT3/flk-2 receptors (1,2). It plays a critical role in activation and growth in a number of cell types including hematopoietic stem cells, mast cells, melanocytes, and germ cells (3). Upon binding with its stem cell factor (SCF) ligand, 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 PLCγ, the p85 subunit of PI3 kinase, SHP2, and CrkL (4). Molecular lesions that impair the kinase activity of c-Kit are associated with a variety of developmental disorders (5), and mutations that constitutively activate c-Kit can lead to pathogenesis of mastocytosis and gastrointestinal stromal tumors (6). 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 (7).
Application Methods: Flow Cytometry, IHC-Leica® Bond™, Immunofluorescence (Immunocytochemistry), Immunohistochemistry (Paraffin), Western Blotting
Background: Human p14 ARF (p19 ARF in mouse) is a pro-apoptotic cell cycle regulator frequently inactive in human tumors (1). Basal expression of p14 ARF is low in most cell types, but accumulation of this protein occurs in response to oncogene expression (2,3). Increased p14 ARF levels facilitate MDM2 degradation, leading to increased p53 protein levels and subsequent cell cycle arrest and/or apoptosis (4). While most p14 ARF signaling has traditionally thought to be p53-dependent, more recent reports have described p53-independent p14 ARF signaling leading to cell cycle arrest and apoptosis (5,6).