| Post Translational Modifications | C3b is rapidly split in two positions by factor I and a cofactor to form iC3b (inactivated C3b) and C3f which is released. Then iC3b is slowly cleaved (possibly by factor I) to form C3c (beta chain + alpha' chain fragment 1 + alpha' chain fragment 2), C3dg and C3f. Other proteases produce other fragments such as C3d or C3g. C3a is further processed by carboxypeptidases to release the C-terminal arginine residue generating the acylation stimulating protein (ASP). Levels of ASP are increased in adipocytes in the postprandial period and by insulin and dietary chylomicrons. Phosphorylated by FAM20C in the extracellular medium. (Microbial infection) C3 is cleaved by Staphylococcus aureus aureolysin.this cleavage renders C3a and C3b inactive. C3b is rapidly degraded by host factors CFH and CFI preventing its deposition on the bacterial surface while C3a is further inactivated by aureolysin. (Microbial infection) Complement C3 beta chain is cleaved and inactivated by S.pyogenes SpeB. (Microbial infection) Cleaved by N.meningitidis NalP between Leu-744 and Gly-754, generating a slightly shorter C3 alpha form and a slightly longer C3 beta form. The C3b-like fragment is degraded in the presence of the complement regulators CFH and CFI, preventing its deposition on the bacterial surface. |
| Function | C3 plays a central role in the activation of the complement system. Its processing by C3 convertase is the central reaction in both classical and alternative complement pathways. After activation C3b can bind covalently, via its reactive thioester, to cell surface carbohydrates or immune aggregates. Derived from proteolytic degradation of complement C3, C3a anaphylatoxin is a mediator of local inflammatory process. In chronic inflammation, acts as a chemoattractant for neutrophils. It induces the contraction of smooth muscle, increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes. C3-beta-c: Acts as a chemoattractant for neutrophils in chronic inflammation. Acylation stimulating protein: Adipogenic hormone that stimulates triglyceride (TG) synthesis and glucose transport in adipocytes, regulating fat storage and playing a role in postprandial TG clearance. Appears to stimulate TG synthesis via activation of the PLC, MAPK and AKT signaling pathways. Ligand for C5AR2. Promotes the phosphorylation, ARRB2-mediated internalization and recycling of C5AR2. |
| Protein Name | Complement C3C3 And Pzp-Like Alpha-2-Macroglobulin Domain-Containing Protein 1 Cleaved Into - Complement C3 Beta Chain - C3-Beta-CC3bc - Complement C3 Alpha Chain - C3a Anaphylatoxin - Acylation Stimulating ProteinAspC3adesarg - Complement C3b Alpha' Chain - Complement C3c Alpha' Chain Fragment 1 - Complement C3dg Fragment - Complement C3g Fragment - Complement C3d Fragment - Complement C3f Fragment - Complement C3c Alpha' Chain Fragment 2 |
| Database Links | Reactome: R-HSA-173736Reactome: R-HSA-174577Reactome: R-HSA-198933Reactome: R-HSA-375276Reactome: R-HSA-381426Reactome: R-HSA-418594Reactome: R-HSA-6798695Reactome: R-HSA-8957275Reactome: R-HSA-9660826Reactome: R-HSA-977606 |
| Cellular Localisation | Secreted |
| Alternative Protein Names | Complement C3 proteinC3 And Pzp-Like Alpha-2-Macroglobulin Domain-Containing Protein 1 Cleaved Into - Complement C3 Beta Chain - C3-Beta-C proteinC3bc - Complement C3 Alpha Chain - C3a Anaphylatoxin - Acylation Stimulating Protein proteinAsp proteinC3adesarg - Complement C3b Alpha' Chain - Complement C3c Alpha' Chain Fragment 1 - Complement C3dg Fragment - Complement C3g Fragment - Complement C3d Fragment - Complement C3f Fragment - Complement C3c Alpha' Chain Fragment 2 proteinC3 proteinCPAMD1 protein |
Information sourced from Uniprot.org
