complement component 5 complement component 5 complement component 5 is a protein that in humans is encoded by the c5 gene. c5available structurespdbortholog search: pdbe rcsb list of pdb id codes1cfa, 1kjs, 1xwe, 3cu7, 3hqa, 3hqb, 3kls, 3km9, 3prx, 3pvm, 4a5w, 4e0s, 4p39, 4uu9, 5i5k, 5hce, 5hcc, 5hcdidentifiersaliasesc5, c5d, c5a, c5b, cpamd4, eclzb, complement component 5, complement c5external idsomim: 120900 mgi: 96031 homologene: 20412 genecards: c5 gene location (human)chr.chromosome 9 (human)band9q33.2start120,932,642 bpend121,075,195 bpgene location (mouse)chr.chromosome 2 (mouse)band2 b|2 23.22 cmstart34,873,343 bpend34,951,450 bprna expression patternbgeehumanmouse (ortholog)top expressed inright lobe of liveroocytebody of pancreassecondary oocyteachilles tendontibial nerveleft coronary arterypopliteal arterybody of stomachlower lobe of lungtop expressed inleft lobe of liverright lung lobeleft lungleft lung lobegallbladdersecondary oocytecarotid bodyhabenulathoracic diaphragmconjunctival fornixmore reference expression databiogpsmore reference expression datagene ontologymolecular 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 / quickgoorthologsspecieshumanmouseentrez72715139ensemblensg00000106804ensmusg00000026874uniprotp01031p06684refseq (mrna)nm_001735nm_001317163nm_001317164nm_010406refseq (protein)np_001304092np_001304093np_001726np_034536location (ucsc)chr 9: 120.93 – 121.08 mbchr 2: 34.87 – 34.95 mbpubmed searchwikidataview/edit humanview/edit mouse complement component 5 is involved in the complement system. it is cleaved into c5a and c5b: c5a plays an important role in chemotaxis. 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. 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. therapeutic applications the drug eculizumab (trade name soliris) prevents cleavage of c5 into c5a and c5b. complement system pathway membrane attack complex.