Complement component 5

C5
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	1CFA, 1KJS, 1XWE, 3CU7, 3HQA, 3HQB, 3KLS, 3KM9, 3PRX, 3PVM, 4A5W, 4E0S, 4P39, 4UU9, 5I5K, 5HCE, 5HCC, 5HCD
Identifiers
Aliases	C5, C5D, C5a, C5b, CPAMD4, ECLZB, complement component 5, complement C5
External IDs	OMIM: 120900; MGI: 96031; HomoloGene: 20412; GeneCards: C5; OMA:C5 - orthologs
Gene location (Human)
Chr.	Chromosome 9 (human)
End	121,075,195 bp
Gene location (Mouse)
Chr.	Chromosome 2 (mouse)
End	34,951,450 bp
RNA expression pattern
	Top expressed in
	right lobe of liver; ; oocyte; ; body of pancreas; ; secondary oocyte; ; Achilles tendon; ; gonad; ; tibial nerve; ; testicle; ; Descending thoracic aorta; ; ventricular zone;
	Top expressed in
	left lobe of liver; ; right lung lobe; ; left lung; ; left lung lobe; ; gallbladder; ; granulocyte; ; fetal liver hematopoietic progenitor cell; ; human fetus; ; Neural groove; ; embryo;
	More reference expression data
	More reference expression data
Gene ontology
Molecular function	chemokine activity; protein binding; endopeptidase inhibitor activity; signaling receptor binding;
Cellular component	extracellular region; extracellular exosome; membrane attack complex; extracellular space;
Biological process	G protein-coupled receptor signaling pathway; cytolysis; complement activation, alternative pathway; immune system process; complement activation; response to stress; in utero embryonic development; positive regulation of angiogenesis; chemotaxis; cell surface receptor signaling pathway; complement activation, classical pathway; positive regulation of vascular endothelial growth factor production; inflammatory response; regulation of complement activation; negative regulation of macrophage chemotaxis; negative regulation of endopeptidase activity; innate immune response; cell chemotaxis;
	Sources:Amigo / QuickGO
Orthologs
	727
	15139
	ENSG00000106804
	ENSMUSG00000026874
	P01031
	P06684
	NM_001735; NM_001317163; NM_001317164
	NM_010406
	NP_001304092; NP_001304093; NP_001726
	NP_034536
	Wikidata
View/Edit Human	View/Edit Mouse

Complement component 5 is a protein that in humans is encoded by the C5 gene.^[5]

Complement component 5 is involved in the complement system. It is cleaved into C5a and C5b:

C5a plays an important role in chemotaxis.^[6]
C5b forms the first part of the complement membrane attack complex.

Deficiency is thought to cause Leiner's disease.

Function

Complement component 5 is the fifth component of complement, which plays an important role in inflammatory and cell killing processes. This protein is composed of alpha and beta polypeptide chains that are linked by a disulfide bridge. An activation peptide, C5a, which is an anaphylatoxin that possesses potent spasmogenic and chemotactic activity, is derived from the alpha polypeptide via cleavage with a C5-convertase. The C5b macromolecular cleavage product can form a complex with the C6 complement component, and this complex is the basis for formation of the membrane attack complex, which includes additional complement components.^[5]

Clinical significance

Mutations in this gene cause complement component 5 deficiency, a disease where patients show a propensity for severe recurrent infections. Defects in this gene have also been linked to a susceptibility to liver fibrosis and to rheumatoid arthritis.^[5]