The c-kit protein, or the CD117 antigen, is a receptor tyrosine kinase (RTK) encoded by the KIT gene. It is a transmembrane protein primarily found on the surface of various cell types, including hematopoietic stem cells, mast cells, melanocytes, and germ cells. The c-kit protein plays a crucial role in cell survival, proliferation, migration, and differentiation by binding to its ligand, stem cell factor (SCF).
Functionally, the c-kit protein acts as a growth factor receptor, transmitting signals from outside the cell to the inside, subsequently activating various intracellular signaling pathways. These pathways regulate cell growth, survival, and development. Activation of the c-kit protein can initiate processes such as hematopoiesis, melanogenesis, and oogenesis, among others.
Mutations in the KIT gene, leading to altered expression or function of the c-kit protein, have been implicated in the development of several diseases. For instance, activating mutations in c-kit are associated with certain types of cancers, including gastrointestinal stromal tumors (GISTs) and acute myeloid leukemia (AML). In addition, deficiencies or dysfunction in c-kit expression can result in disorders such as piebaldism, mastocytosis, and infertility. Pharmacological targeting of the c-kit protein has therefore become a viable strategy in the treatment of these diseases, with inhibitors specifically designed to block the abnormal activity of the protein.
