Complement C3
Complement C3 (C3, formerly complement component 3; also CPAMD1 and ARMD9) is a secreted protein that plays a central role in activation of the complement system. Its cleavage products include C3a and C3b, and the protein also acts as a chemoattractant for neutrophils in chronic inflammation. Browse Assay Genie's current range of Complement C3 research reagents below, or read on for the biology behind the target.
Complement C3 sits at the centre of the complement system. Its activation is required for both the classical and the alternative complement pathways, which makes it a convergence point for these routes of immune activation. In UniProt, Complement C3 is also described as a chemoattractant for neutrophils in chronic inflammation. The protein is found in the secreted fraction and at the cell surface.
The C3 gene encodes a preproprotein that is processed proteolytically into alpha and beta subunits, which together form the mature protein. This mature protein is then processed further to give numerous peptide products. Among them, the C3a peptide, known as the C3a anaphylatoxin, modulates inflammation and has antimicrobial activity. C3b is another commonly cited product name, and researchers often look for it alongside C3a when studying complement activation. Any C3 antibody, C3 ELISA kit or recombinant C3 protein is therefore best matched to the form of the molecule under study, whether precursor, subunit or cleavage fragment.
HGNC classifies C3 within receptor ligands, within the C3 and PZP-like, alpha-2-macroglobulin domain containing group, and among complement system activation components. Earlier names include complement component 3, and the aliases CPAMD1 and ARMD9 appear in the literature. Mutations in the C3 gene are associated with atypical haemolytic uraemic syndrome and age-related macular degeneration in human patients, which keeps the protein in focus for both immunology and disease research. Mouse and rat both carry a C3 ortholog.
C3 activation is required for both the classical and alternative pathways, so it is a core readout of complement activity.
The C3a anaphylatoxin modulates inflammation, and C3 acts as a neutrophil chemoattractant in chronic inflammation.
The C3a peptide has antimicrobial activity, linking C3 processing to host defence mechanisms.
Mutations in C3 are associated with atypical haemolytic uraemic syndrome and age-related macular degeneration in patients.
Complement C3 plays a central role in activating the complement system, and its activation is needed for both the classical and alternative pathways. Its peptide products, including the C3a anaphylatoxin, modulate inflammation. UniProt also notes a role as a neutrophil chemoattractant in chronic inflammation.
The gene is also called complement component 3, CPAMD1 and ARMD9, and C3a and C3b are listed as aliases. The preproprotein is cleaved into alpha and beta subunits that form the mature protein, which is processed further into numerous peptide products.
Yes to both. Mutations in C3 are associated with atypical haemolytic uraemic syndrome and age-related macular degeneration in human patients. Mouse and rat each have a C3 ortholog; check the datasheet of any product for its validated reactivity.
Other complement components, C3 cleavage products and receptors that act in the same activation pathways.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P01024; product specifications from Assay Genie datasheets.