Macrophage Colony Stimulating Factor (CSF1) Active Protein

The protein encoded by this gene is a cytokine that controls the production, differentiation, and function of macrophages. The active form of the protein is found extracellularly as a disulfide-linked homodimer, and is thought to be produced by proteolytic cleavage of membrane-bound precursors. The encoded protein may be involved in development of the placenta. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Sep 2011]

Function: Cytokine that plays an essential role in the regulation of survival, proliferation and differentiation of hematopoietic precursor cells, especially mononuclear phagocytes, such as macrophages and monocytes. Promotes the release of proinflammatory chemokines, and thereby plays an important role in innate immunity and in inflammatory processes. Plays an important role in the regulation of osteoclast proliferation and differentiation, the regulation of bone resorption, and is required for normal bone development. Required for normal male and female fertility. Promotes reorganization of the actin cytoskeleton, regulates formation of membrane ruffles, cell adhesion and cell migration. Plays a role in lipoprotein clearance. Ref.19 Ref.21 Ref.22 Ref.23

Subunit structure: Homodimer or heterodimer; disulfide-linked. Interacts with CSF1R. Ref.15 Ref.16 Ref.17 Ref.23

Subcellular location: Cell membrane; Single-pass membrane protein Ref.15 Ref.16. Processed macrophage colony-stimulating factor 1: Secreted › extracellular space Ref.15 Ref.16.

Post-translational modification: N- and O-glycosylated. Glycosylation and proteolytic cleavage yield different soluble forms. One high molecular weight soluble form is a proteoglycan containing chondroitin sulfate. O-glycosylated with core 1 or possibly core 8 glycans. Isoform 1 is N- and O-glycosylated. Isoform 3 is only N-glycosylated. Ref.15 Ref.16 Ref.24 Ref.25

Involvement in disease: Aberrant expression of CSF1 or CSF1R can promote cancer cell proliferation, invasion and formation of metastases. Overexpression of CSF1 or CSF1R is observed in a significant percentage of breast, ovarian, prostate, and endometrial cancers. Ref.19 Ref.21Aberrant expression of CSF1 or CSF1R may play a role in inflammatory diseases, such as rheumatoid arthritis, glomerulonephritis, atherosclerosis, and allograft rejection. Ref.19 Ref.21