SIRP beta 1/CD172b: Proteins and Enzymes

SIRP beta 1 is a type I transmembrane protein belonging to the SIRP family within the Ig superfamily. Members of this family are characterized by an extracellular region containing a V-set Ig domain with a J-like sequence and two C1-set Ig domains. Unlike SIRP alpha that has cytoplasmic ITIM domains, SIRP beta 1 possesses positively charged residues that allow association with ITAM motif-containing adaptor molecules. SIRP beta 1 is expressed on cells of monocyte, macrophage or dendritic lineages.