Recombinant Human Complement component C1q receptor (CD93), partial (Active)

Function

Cell surface receptor that plays a role in various physiological processes including inflammation, phagocytosis, and cell adhesion. Plays a role in phagocytosis and enhances the uptake of apoptotic cells and immune complexes by acting as a receptor for defense collagens including surfactant protein A/SFTPA1, C1q, and mannose-binding lectin (MBL2) (PubMed:7977768). Plays a role in the regulation of endothelial cell function and adhesion by activating angiogenesis (PubMed:24809468). Mechanistically, exerts its angiogenic function by associating with beta-dystroglycan, leading to SRC-dependent phosphorylation and subsequent recruitment of CBL. In turn, CBL provides a docking site for downstream signaling components, such as CRKL to enhance cell migration (PubMed:26848865). Participates in angiogenesis also by acting as a receptor for the ECM pan-endothelial glycoprotein multimerin-2/MMRN2 and IGFBP7 ligands (PubMed:28671670, PubMed:36265539, PubMed:38218180). Both ligands play a non-redundant role in CD93-mediated endothelial cell function (PubMed:38218180). Acts as a key regulator of endothelial barrier function through modulating VEGFR2 function (By similarity)

Subcellular Location

Cell membrane (Single-pass type I membrane protein)

Tissue Specificity

Highly expressed in endothelial cells, platelets, cells of myeloid origin, such as monocytes and neutrophils. Not expressed in cells of lymphoid origin

Subunit

(Microbial infection) Interacts with hepatitis virus C/HCV core protein

• Nepomuceno R.R. et al. cDNA cloning and primary structure analysis of C1qR(P), the human C1q/MBL/SPA receptor that mediates enhanced phagocytosis in vitro. — Immunity (1997)
• Steinberger P. et al. Identification of human CD93 as the phagocytic C1q receptor (C1qRp) by expression cloning. — J. Leukoc. Biol. (2002)
• Deloukas P. et al. The DNA sequence and comparative analysis of human chromosome 20. — Nature (2001)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Geertsma M.F. et al. Binding of surfactant protein A to C1q receptors mediates phagocytosis of Staphylococcus aureus by monocytes. — Am. J. Physiol. (1994)
• Ghebrehiwet B. et al. Evidence that the two C1q binding membrane proteins, gC1q-R and cC1q-R, associate to form a complex. — J. Immunol. (1997)
• McGreal E.P. et al. Human C1qRp is identical with CD93 and the mNI-11 antigen but does not bind C1q. — J. Immunol. (2002)
• Nepomuceno R.R. et al. C1qRP is a heavily O-glycosylated cell surface protein involved in the regulation of phagocytic activity. — J. Immunol. (1999)