FLT3 is an important cell surface marker expressed in certain types of hematopoietic progenitors in the bone marrow. Multipotent progenitors and common lymphoid progenitors express high surface levels of FLT3.
FLT3 was originally isolated as a hematopoietic progenitor cell-specific kinase and belongs to the class III receptor tyrosine-kinase (RTK) family, which also includes c-Fms, c-Kit, and platelet-derived growth factor receptor (PDGFR). FLT3 contains five extracellular immunoglobulin-like domains, a transmembrane domain, a juxtamembrane domain, and two tyrosine-kinase domains that are linked through tyrosine-kinase insert. Cytoplasmic FLT3 undergoes glycosylation, which promotes localization of the receptor to the membrane. Signaling through FLT3 plays a role in cell survival, proliferation, and differentiation....