C-Kit Blocking Peptide

This gene encodes the human homolog of the proto-oncogene c-kit. C-kit was first identified as the cellular homolog of the feline sarcoma viral oncogene v-kit. This protein is a type 3 transmembrane receptor for MGF (mast cell growth factor, also known as stem cell factor). Mutations in this gene are associated with gastrointestinal stromal tumors, mast cell disease, acute myelogenous lukemia, and piebaldism. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Kit: a receptor tyrosine kinase and a member of the subfamily that includes PDGF, CSF-1 and FLT-3/flk-2 receptors. Receptor for stem cell factor. Plays a critical role in hematopoietic stem cell, mast cell, melanocyte and germ cell development. Ligand binding induces autophosphorylation, dimerization and activation, leading to the recruitment and phosphorylation of downstream SH2-containing signaling components including PLC-gamma, PI3 kinase p85, SHP2 and CrkL, linking c-Kit to various cell signaling pathways. 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 hyperplasia and tumorigenesis. Activating mutations cause >90% of gastrointestinal stromal tumors (GIST); successfully treated with inhibitors Gleevec (imatinib, Glivec) and Sutent (Sutinib, SU11248). Activating mutations also induce mastocytosis. Autocrine/paracrine stimulation may drive some lung and other tumors. Loss of expression associated with melanoma progression. Familial loss of function mutations cause piebaldism, with defects in hair and skin pigmentation due to lack of melanocytes.

Protein type: Membrane protein, integral; Kinase, protein; Protein kinase, TK; Oncoprotein; EC 2.7.10.1; Protein kinase, tyrosine (receptor); TK group; PDGFR family

Chromosomal Location of Human Ortholog: 4q12

Cellular Component: extracellular space; internal side of plasma membrane; mast cell granule; acrosome; plasma membrane; integral to membrane; intercellular junction; external side of plasma membrane

Molecular Function: protein binding; protein homodimerization activity; protease binding; metal ion binding; protein-tyrosine kinase activity; cytokine binding; stem cell factor receptor activity; receptor signaling protein tyrosine kinase activity; transmembrane receptor protein tyrosine kinase activity; ATP binding

Biological Process: nerve growth factor receptor signaling pathway; activation of MAPK activity; somatic stem cell maintenance; germ cell programmed cell death; positive regulation of JAK-STAT cascade; lymphoid progenitor cell differentiation; positive regulation of long-term neuronal synaptic plasticity; positive regulation of tyrosine phosphorylation of Stat3 protein; regulation of cell shape; epithelial cell proliferation; germ cell migration; erythrocyte differentiation; somatic stem cell division; T cell differentiation; fibroblast growth factor receptor signaling pathway; embryonic hemopoiesis; mast cell chemotaxis; stem cell differentiation; detection of mechanical stimulus involved in sensory perception of sound; positive regulation of phosphoinositide 3-kinase cascade; positive regulation of tyrosine phosphorylation of Stat1 protein; immature B cell differentiation; positive regulation of transcription factor activity; regulation of pigmentation during development; glycosphingolipid metabolic process; mast cell cytokine production; peptidyl-tyrosine phosphorylation; protein amino acid autophosphorylation; signal transduction; myeloid progenitor cell differentiation; ovarian follicle development; positive regulation of MAPKKK cascade; positive regulation of cell proliferation; melanocyte differentiation; negative regulation of programmed cell death; visual learning; hemopoiesis; inflammatory response; positive regulation of Notch signaling pathway; epidermal growth factor receptor signaling pathway; lamellipodium biogenesis; phosphoinositide-mediated signaling; dendritic cell cytokine production; cytokine and chemokine mediated signaling pathway; male gonad development; stem cell maintenance; positive regulation of phosphoinositide 3-kinase activity; mast cell degranulation; regulation of cell proliferation; positive regulation of pseudopodium formation; gut development; positive regulation of tyrosine phosphorylation of Stat5 protein; pigmentation; actin cytoskeleton reorganization; innate immune response; spermatogenesis; spermatid development; positive regulation of cell migration

Disease: Gastrointestinal Stromal Tumor; Mast Cell Disease; Piebald Trait; Testicular Germ Cell Tumor