Recombinant Human SIRP beta 1/CD172b Protein (C09-1613-024)

Protein Function:Signal-regulatory protein beta 1 (SIRP beta 1) is a disulfide-linked type I membrane glycoprotein that belongs to the SIRP/SHPS (CD172) family of the immunoglobulin (Ig) superfamily. The SIRP family are paired receptors that have similar extracellular domains but differing C-terminal domains and functions. Members of this family are characterized by an extracellular region containing a V-set Ig domain containing a J-like sequence and two C1-set Ig domains. The extracellular domain contains 3 intramolecular disulfide bonds and one interchain disulfide at Cys320. Positively charged residues within the transmembrane domain mediate interactions with DAP12 proteins which contain immunoreceptor tyrosine-based activation motifs (ITAMs). Proteins in the SIRP family are typically expressed in cells of monocyte, macrophage or dendritic lineages. Human SIRP beta 1 shares a 57% sequence identity with mouse and rat SIRP beta 1. SIRP beta 1 has a relatively short cytoplasmic region and lacks the signaling motifs for association with phosphatases. However, formation of the SIRP beta 1/DAP12 complex in myeloid cells induce tyrosine phosphorylation, mitogen-activated protein kinase activation, and cellular activation. Engagement of SIRP beta 1 by specific monoclonal antibodies promoted Fc gamma receptor-dependent or -independent phagocytosis in mouse peritoneal macrophages. Surfactant protein D (Sp-D) has been shown to bind SIRP alpha and SIRP beta 1 in a calcium-dependent and sugar-specific manner on a distinct binding site from CD47. Although the SIRP beta 1 extracellular regions share a high degree of homology with the SIRP alpha, SIRP beta 1 has been shown not to bind CD47. Specification: Animal Free, Carrier Free, ≥90%(SDS-PAGE)