Recombinant Human SIRP gamma/CD172g Fc Chimera Protein, CF

Recombinant Human SIRP gamma/CD172g Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: SIRP gamma/CD172g

Signal regulatory protein gamma (SIRP gamma, designated CD172g), also called SIRP beta 2, is a monomeric 45-47 kDa type I transmembrane protein belonging to the SIRP/SHPS (CD172) family of the Ig superfamily (1-5). SIRP members are "paired receptors" with homology in the extracellular domain but variability in the C‑terminus and signaling function (1, 2). The 387 amino acid (aa) SIRP gamma sequence contains a 28 aa potential signal sequence, a 332 aa extracellular domain (ECD) with four potential N‑glycosylation sites, a 23 aa transmembrane domain and a 4 aa cytoplasmic sequence. SIRP gamma contains one V-type Ig‑like domain that contains a J‑like sequence and two C1-type Ig‑like domains within its ECD (1, 2). Isoforms that lack one (isoform 2, 276 aa) or two (isoform 3, 170 aa) membrane-proximal C‑type Ig-like domains have been described (5). Within the ECD, human SIRP gamma isoform 1 shares 78% aa identity with human SIRP beta 1, and appears to have structurally similar orthologs only in rhesus monkey and chimpanzee (100% and 91% aa identity, respectively) (2). SIRP gamma is the only SIRP known to be expressed on T cells, CD56^bright NK cells and activated NK cells; it is not expressed on myeloid cells (5, 6). It shows adhesion to CD47, but at lower affinity than SIRP alpha (6). Expression of SIRP gamma on T cells suggests a role as an accessory protein interacting with CD47‑expressing antigen presenting cells (5, 6). Unlike SIRP alpha that has cytoplasmic ITIM domains, and SIRP beta 1 that interacts with DAP-12, SIRP gamma does not contain any obvious signaling motif (1, 2, 6). However, SIRP gamma -mediated adhesion appears to promote antigen-specific T cell proliferation and costimulate T cell activation (5). Engagement of CD47 by SIRP gamma was shown to induce apoptosis on T-cell and monocyte cell lines (6).

Related Research Areas

• Search Immune Checkpoint Targets
• T Cell Migration/Adhesion