CD135

CD135‏‎, also known as FLT3 (Fms-like tyrosine kinase 3), is a protein that in humans is encoded by the FLT3 gene. It is a member of the class III receptor tyrosine kinase (RTK) family, which includes c-Kit, PDGFR, and FLT1. CD135 plays a crucial role in the survival, proliferation, and differentiation of hematopoietic cells.

Structure

CD135 is a type III receptor tyrosine kinase, characterized by five immunoglobulin-like domains in the extracellular region. The intracellular region of CD135 contains a juxtamembrane domain, a tyrosine kinase domain, and a C-terminal tail.

Function

CD135 is expressed on the surface of many hematopoietic progenitor cells. The binding of FLT3 ligand (FLT3L) to CD135 triggers dimerization and autophosphorylation of the receptor, leading to the activation of multiple signal transduction pathways. These pathways include the RAS/MAPK pathway, the PI3K/AKT pathway, and the STAT pathway, which regulate cell survival, proliferation, and differentiation.

Clinical significance

Mutations in the FLT3 gene are associated with poor prognosis in acute myeloid leukemia (AML). These mutations often result in constitutive activation of the receptor, leading to uncontrolled cell proliferation. FLT3 inhibitors are currently being developed as targeted therapies for AML.

See also

• Receptor tyrosine kinase
• Acute myeloid leukemia
• Signal transduction