C1S

This gene encodes a serine protease, which is a major constituent of the human complement subcomponent C1. C1s associates with two other complement components C1r and C1q in order to yield the first component of the serum complement system. Defects in this gene are the cause of selective C1s deficiency.

complement C1s

C1s B chain is a serine protease that combines with C1q and C1r to form C1, the first component of the classical pathway of the complement system. C1r activates C1s so that it can, in turn, activate C2 and C4.

Complement activation Source: Reactome
Complement activation, classical pathway Source: Reactome
Innate immune response Source: UniProtKB-KW
Regulation of complement activation Source: Reactome

Blood microparticle; Extracellular region; Extracellular space

Complement component C1s deficiency (C1SD): A rare defect resulting in C1 deficiency and impaired activation of the complement classical pathway. C1 deficiency generally leads to severe immune complex disease with features of systemic lupus erythematosus and glomerulonephritis.
Ehlers-Danlos syndrome, periodontal type, 2 (EDSPD2):A form of Ehlers-Danlos syndrome, a connective tissue disorder characterized by hyperextensible skin, atrophic cutaneous scars due to tissue fragility and joint hyperlaxity. EDSPD2 is characterized by the association of typical features of Ehlers-Danlos syndrome with gingival recession and severe early-onset periodontal disease, leading to premature loss of permanent teeth. EDSPD2 transmission pattern is consistent with autosomal dominant inheritance.

The iron and 2-oxoglutarate dependent 3-hydroxylation of aspartate and asparagine is (R) stereospecific within EGF domains.