Human Colony Stimulating Factor 1 (CSF1), also known as macrophage colony-stimulating factor (M-CSF), is a secreted cytokine that causes hematopoietic stem cells to differentiate into macrophages or other related cell types. This growth factor is involved in the proliferation, differentiation, and survival of hematopoietic precursor cells, especially mononuclear phagocytes, such as macrophages and monocytes. CSF1 stimulates increased phagocytic and chemotactic activity of macrophages and monocytes. For hematopoietic progenitors, CSF1 interacts with membrane receptor CSR1R or M-CSF-R and modulates proliferation. The active form of CSF1 is found extracellularly as a disulfide-linked homodimer and is thought to be produced by proteolytic cleavage of membrane-bound precursors. Upon binding of the ligand to extracellular Ig domains, CSF1R dimerizes noncovalently and autophosphorylates several tyrosine residues. This first wave of CSF1R tyrosine phosphorylation creates phosphotyrosine-binding domains to which effector proteins can bind and initiate various cellular responses. CSF1 includes an Fc-fusion tag from human IgG1. Lyophilized powder.
