C2
C2 (complement C2, formerly complement component 2) is a secreted serum glycoprotein of the classical complement pathway. It supplies the catalytic activity of the C3 and C5 convertase complexes, which drive the downstream steps of complement activation. Browse Assay Genie's current range of C2 research reagents below, or read on for the biology behind the target.
C2 is the catalytic component of the complement C3 and C5 convertase complexes. After complement activation, activated C1 cleaves C2 into C2a and C2b. The serine proteinase fragment C2a is recruited to the surface of pathogens by the complement C4b opsonin, forming the C3 convertase. Together with C3b and C4b opsonins, it forms the C5 convertase.
As part of the C3 convertase, C2 cleaves and activates C3 into the C3a anaphylatoxin and the C3b opsonin, the next components of the complement pathways. As part of the C5 convertase, it cleaves and activates C5 into the C5a anaphylatoxin and C5b, a component of the membrane attack complex. C2 is therefore a central link between recognition by the classical pathway and the effector arms of complement.
The protein belongs to the peptidase S1 family, and HGNC classifies it among serine proteases, Sushi domain containing proteins and complement system activation components. It is found in the secreted fraction and at the cell surface. The C2 gene lies within the class III region of the MHC on the short arm of chromosome 6, and alternative splicing produces multiple transcript variants that encode distinct isoforms. C2 deficiency has been reported in association with certain autoimmune diseases, and SNPs in the gene have been associated with altered susceptibility to age-related macular degeneration. A mouse ortholog, also named C2, is annotated.
C2 is the catalytic subunit of both the C3 and C5 convertases, making it a key protein for studying classical pathway activation.
By enabling cleavage of C3 and C5, C2 contributes to opsonin deposition, anaphylatoxin release and membrane attack complex formation against pathogens.
C2 deficiency has been reported to associate with certain autoimmune diseases, making the protein relevant to immune dysregulation research.
SNPs in the C2 gene have been associated with altered susceptibility to age-related macular degeneration, linking complement genetics to ocular disease.
C2 is the catalytic component of the C3 and C5 convertases. Once C1 cleaves it, the C2a serine protease fragment joins C4b, or C3b and C4b, on pathogen surfaces. The convertases then cleave C3 into C3a and C3b, and C5 into C5a and C5b.
The HGNC name is complement C2, and the previous name was complement component 2. Activated C1 cleaves the protein into C2a and C2b. Alternative splicing of the C2 gene yields multiple transcript variants encoding distinct isoforms, and further variants have been described without full-length sequence.
C2 deficiency has been reported in association with certain autoimmune diseases, and SNPs in the gene are associated with altered susceptibility to age-related macular degeneration. A mouse ortholog named C2 exists; check the datasheet of any product for its validated reactivity.
Other complement components, convertase substrates and classical pathway proteins with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P06681; product specifications from Assay Genie datasheets.