. "Authored: Garapati, P V, 2011-07-11"^^ . "Edited: Garapati, P V, 2011-07-11"^^ . "Reviewed: R\u00F6nnstrand, L, 2011-08-22"^^ . "Two human isoforms of KIT have been identified, resulting from alternative splicing. They are characterized by the presence or absence of a tetrapeptide sequence (GNNK 510-513 aa) in the extracellular part of the juxtamembrane region and designated GNNK+ (Kit) or GNNK- (KitA) (Piao et al. 1994). The isoforms are co-expressed in most tisuues, with the GNNK- form predominating (Reith et al. 1991). No difference in ligand affinity was observed (Caruana et al. 1999).
KIT belongs to the type III tyrosine kinase receptor family, with five extracellular immunoglobulin (Ig)-like domains, a single transmembrane region, an inhibitory cytoplasmic juxtamembrane domain, and a split cytoplasmic kinase domain separated by a kinase insert segment and a cytoplasmic tail (Mol et al. 2003).
Signaling by KIT occurs following SCF binding. SCF homodimers binds to the first three Ig-like domains of KIT in the regions between aa L104-D122 and R146-D153 (Mendiaz et al. 1996, Matous et al. 1996) which leads to dimerization which is further stabilized by Ig-like domains 3-4 (Yuzawa et al., 2007)."^^ . . . . . . . . . . . . . . . . . . "Interaction of KIT and sSCF"^^ . . . .