| Function | Serine protease component of the complement C1 complex, a multiprotein complex that initiates the classical pathway of the complement system, a cascade of proteins that leads to phagocytosis and breakdown of pathogens and signaling that strengthens the adaptive immune system. C1R catalyzes the first enzymatic step in the classical complement pathway: it is activated by the C1Q subcomplex of the C1 complex, which associates with IgG or IgM immunoglobulins complexed with antigens to form antigen-antibody complexes on the surface of pathogens. Immunoglobulin-binding promotes the autocatalytic cleavage and activation of C1R. Activated C1R then cleaves and activates C1S, the second protease of the classical complement pathway. It is unclear if C1R activates C1S within single, strained C1 complexes or between neighboring C1 complexes on surfaces. |
| Protein Name | Complement C1r SubcomponentComplement Component 1 Subcomponent R Cleaved Into - Complement C1r Subcomponent Heavy ChainComplement C1r Subcomponent Chain A - Complement C1r Subcomponent Light ChainComplement C1r Subcomponent Chain B |
| Database Links | Reactome: R-HSA-166663Reactome: R-HSA-173623Reactome: R-HSA-977606 |
| Cellular Localisation | SecretedCell SurfaceRecruited To The Surface Of Pathogens By The C1q Subcomplex |
| Alternative Protein Names | Complement C1r Subcomponent proteinComplement Component 1 Subcomponent R Cleaved Into - Complement C1r Subcomponent Heavy Chain proteinComplement C1r Subcomponent Chain A - Complement C1r Subcomponent Light Chain proteinComplement C1r Subcomponent Chain B proteinC1R protein |
Information sourced from Uniprot.org
