Description: 7411-65-6

Description: M-CSF receptor, the product of the c- fms protooncogene, is a member of the type III subfamily of receptor tyrosine kinases that also includes receptors for SCF and PDGF. These receptors each contain five immunoglobulinlike domains in their extracellular domain (ECD) and a split kinase domain in their intracellular region. M-CSF receptor is expressed primarily on cells of the monocyte/macrophage lineage, dendritic cells, stem cells and in the developing placenta. Human M-CSF receptor cDNA encodes a 972 amino acid (aa) type I membrane protein with a 19 aa signal peptide, a 493 aa extracellular region containing the ligandbinding domain, a 25 aa transmembrane domain, and a 435 aa cytoplasmic domain. The human MCSF R ECD shares 60%, 64%, 72%, 75%, 75%, and 76% aa identity with mouse, rat, bovine, canine, feline, and equine M-CSF R, respectively. Activators of protein kinase C induce TACE/ADAM17 cleavage of the MCSF receptor, releasing the functional ligandbinding extracellular domain. M-CSF binding induces receptor homodimerization, resulting in transphosphorylation of specific cytoplasmic tyrosine residues and signal transduction. The intracellular domain of activated MCSF R binds more than 150 proteins that affect cell proliferation, survival, differentiation and cytoskeletal reorganization. Among these, PI3-Kinase, P42/44 ERK, and cCbl are key transducers of M-CSF-R signals. M-CSF R engagement is continuously required for macrophage survival and regulates lineage decisions and maturation of monocytes, macrophages, osteoclasts, and DC. M-CSF -R and integrin αvβ3 share signaling pathways during osteoclastogenesis and deletion of either causes osteopetrosis. In the brain, microglia expressing increased M-CSF-R are concentrated with Alzheimers aβ peptide, but their role in pathogenesis is unclear.