Signal-regulatory protein beta-1 is a protein that in humans is encoded by the SIRPB1 gene. SIRPB1 has also recently been designated CD172B (cluster of differentiation 172B).
The protein encoded by this gene is a member of the signal-regulatory-protein (SIRP) family, and also belongs to the immunoglobulin superfamily. SIRP family members are receptor-type transmembrane glycoproteins known to be involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes. This protein was found to interact with TYROBP/DAP12, a protein bearing immunoreceptor tyrosine-based activation motifs. This protein was also reported to participate in the recruitment of tyrosine kinase SYK. Alternatively spliced transcript variants have been found for this gene.
