Activated Complement Component 1s subcomponent (C1s)

Activated C1s is a serine protease and a key enzymatic subcomponent of the complement system protein complex 1 (C1), which initiates the classical pathway of complement activation. It plays a central role in innate immunity, inflammation, and immune complex clearance. Activated C1s cleaves complement components C4 and C2, leading to the formation of the C3 convertase. It also cleaves non-complement proteins such as MHC I, IGFBP5, LRP6, NPMI, nucleolin, HMGBI. C1s activity is regulated by C1-inhibitor (CINH). Dysregulation or genetic defects in CIS are associated with diseases such as periodontal Ehlers-Danlos syndrome (pEDS) and Hashimoto Disease.

Other names

Activated C1sComplement component C1sC1S

Serine protease inhibition by C1-inhibitor (CINH)