Complement component 1r subcomponent

Complement component 1r subcomponent (C1r) is a serine protease and a key protein in the classical pathway of the complement system. It forms part of the C1 complex along with C1q and C1s. Upon activation by C1q binding to immune complexes, C1r activates C1s, initiating a proteolytic cascade that leads to opsonization, inflammation, and cell lysis. Mutations in C1R are associated with Ehlers-Danlos syndrome, and deficiencies in complement components can contribute to autoimmune diseases.

Other names

Complement C1r subcomponentActivated complement C1rC overbar 1r esterase

Proteolytic cleavage and activation of complement components (e.g., C1s, C4, C2)