|Detection of Gi24/VISTA/B7‑H5 in Mouse Splenocytes by Flow Cytometry. Mouse splenocytes were stained with Rat Anti-Mouse CD4 APC‑conjugated Monoclonal Antibody (Catalog # FAB554A) and either (A) Sheep Anti-Mouse Gi24/VISTA/B7‑H5 Alexa Fluor® 488‑conjugated Antigen Affinity-purified Polyclonal Antibody (Catalog # FAB7005G) or (B) Normal Sheep IgG Alexa Fluor 488 Control (Catalog # IC016G). View our protocol for Staining Membrane-associated Proteins.|
Platelet Receptor Gi24 (also known as Dies1 [Differentiation of ESC-1], SISP1 and C10orf54) is a 55-65 kDa member of the Ig superfamily. It is a transmembrane molecule expressed in bone, on embryonic stem cells (ESCs), and on tumor cell surfaces. On ESCs, Gi24 appears to positively interact with BMP4, potentiating BMP signaling and the transition from an undifferentiated to a differentiated state. On tumor cells, Gi24 both promotes MT1-MMP expression and activity, and serves as a substrate for MT1-MMP. This increases the potential for cell motility. Mature mouse Gi24 is a 277 amino acid (aa) type I transmembrane glycoprotein (aa 33-309). It contains a 149 aa extracellular region (aa 33-191) with one V-type Ig-like domain (aa 33-161) and a 97 aa cytoplasmic domain. Based on human Gi24, mouse Gi24 will likely undergo proteolytic cleavage by MT1-MMP, generating a soluble 30 kDa extracellular fragment, plus a 25-30 kDa membrane-bound fragment. There are two potential isoform variants. One contains a deletion of aa 127-187, while another shows an alternative start site at Met82. Over aa 33-191, mouse Gi24/Dies1 shares 78% and 70% aa identity with rat and human Gi24, respectively.