Kit is composed of five N-glycosylated immunoglobulin domains in the N-terminal extracellular portion that bind SCF, a transmembrane domain, and the carboxy-terminal intracellular tyrosine kinase domain. The binding of SCF autophosphorylates Kit on specific tyrosine residues (Tyr), such as Tyr568/570, Tyr703, Tyr721, and Tyr936. Kit then binds to other cytoplasmic enzymes, such as PI3K and Src kinases, and this complex activates downstream molecules. This activates the Akt-Bad pathway and the Ras-Mek-Erk cascade, which regulate gene expression and cytoskeletal structures, resulting in cell proliferation and survival. (PMID: 28403213)