SIRP alpha (CD172a) Proteins

Protein Information

SIRP alpha (CD172a, signal-regulatory protein alpha) is a receptor-type transmembrane glycoprotein expressed on cells of myeloid origin, including granulocytes, dendritic cells (DCs), macrophages, mast cells and hematopoietic stem cells. SIRP alpha acts as a substrate for several activated tyrosine kinases, including EGFR, PDGFR, src and insulin receptor and is involved in the negative regulation of receptor tyrosine kinase-coupled signaling pathways. The ligand binding of SIRP alpha to integrin-associated protein CD47 results in tyrosine kinase phosphorylation of immunoreceptor tyrosine-based inhibitory motifs (ITIMs) within the cytoplasmic region of SIRP alpha, which mediates the recruitment and activation of the tyrosine phosphatases SHP-1 and SHP-2. Ligation of SIRP alpha with CD47 has been demonstrated in several regulatory processes, including the inhibition of host cell phagocytosis by macrophages and the bi-directional activation of T cells and DCs. SIRP alpha has regulatory effects on cellular responses induced by serum, growth factors, insulin, oncogenes, growth hormones and cell adhesion, and plays a general role in different physiological and pathological processes. Cancer cells highly express CD47, which activates SIRP alpha and inhibits macrophage-mediated destruction of cancerous cell growth.

Synonyms

AI835480; Bit; brain Ig-like molecule with tyrosine-based activation motifs; Brain immunoglobulin like protein with tyrosine - based activation motifs; brain immunological-like with tyrosine-based motifs; brain-immunoglobulin-like molecule with tyrosine-based activation motifs; CD172; CD172 alpha; CD172 antigen-like family member A; CD172A; Inhibitory receptor SHPS-1; macrophage fusion receptor; Macrophage membrane protein MFP150; MFR; mSIRP-alpha1; Myd1; MYD-1; myD-1 antigen; p84; Protein tyrosine phosphatase non-receptor type substrate 1 (SHP substrate 1); protein tyrosine phosphatase, non-receptor type substrate 1; Protein tyrosine phosphatase, non-receptor type substrate 1 (SHP substrate 1); Ptpns1; SHP substrate 1; SHP-1; SHPS1; SHPS-1; signal regulatory protein alpha; signal-regulatory protein alpha; signal-regulatory protein alpha-1; Signal-regulatory protein alpha-2; Signal-regulatory protein alpha-3; SIRP; Sirpa; SIRPalpha; Sirp-alpha-1; SIRPalpha2; Sirp-alpha-2; Sirp-alpha-3; swc3; swine workshop cluster 3 antigen; swine workshop cluster 3 antigen precursor; tyrosine phosphatase SHP substrate 1; tyrosine-protein phosphatase non-receptor type substrate 1