C1

The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION. (mesh:D003172)

Cross-references

• RE:R-HSA-173617
• BEL:C1 Complex
• MESH:D003172 - Complement C1
• SCOMP:C0015
• RE:R-HSA-173615
• RE:R-HSA-173584

Synonyms

Synonym	Reference	Specificity
C1		Exact
c1 complex		Exact
C1-complex		Exact

Incoming Relations

Identifier	Name	Relation
HGNC:1241	C1QA	partof
HGNC:1247	C1S	partof
HGNC:1245	C1QC	partof
HGNC:1242	C1QB	partof
HGNC:1246	C1R	partof

Outgoing Relations

None available.