View source for Complement component 5

{{cs1 config|name-list-style=vanc}}
{{Short description|Protein found in humans}}
{{Infobox_gene}}
'''Complement component 5''' is a [[protein]] that in humans is encoded by the ''C5'' [[gene]].<ref name="entrez">{{cite web | title = C5 complement C5 (Homo sapiens (human)) Gene ID: 727 |date= 29 November 2020| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=727 |website=www.ncbi.nlm.nih.gov |access-date=9 December 2020}}</ref>

Complement component 5 is involved in the [[complement system]]. It is cleaved into [[Complement component 5a|C5a]] and C5b:
* [[Complement component 5a|C5a]] plays an important role in [[chemotaxis]].<ref>{{GeorgiaImmunology|1/phagocyt}}{{Deadlink|date=December 2020}}</ref>
* 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 [[spasm]]ogenic and [[chemotaxis|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 [[complement component 6|C6 complement component]], and this complex is the basis for formation of the membrane attack complex, which includes additional complement components.<ref name="entrez"/>

== 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]].<ref name="entrez"/>

== Therapeutic applications ==

The drug [[eculizumab]] (trade name '''Soliris''') prevents cleavage of C5 into C5a and C5b.<ref>{{cite journal | title=Eculizumab| vauthors=Dubois E, Cohen A| journal=Br J Clin Pharmacol| year=2009| volume=68| pages=318–319| pmc=2766470 |doi=10.1111/j.1365-2125.2009.03491.x | issue=3 | pmid=19740388}}</ref>

== Complement system pathway ==
[[Image:Formowanie_MAC-en.svg|thumb|left|400px|Membrane attack complex.]]
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==References==
{{Reflist}}

==Further reading==
{{refbegin | 2}}
*{{cite journal  | vauthors=Tack BF, Morris SC, Prahl JW |title=Fifth component of human complement: purification from plasma and polypeptide chain structure |journal=Biochemistry |volume=18 |issue= 8 |pages= 1490–7 |year= 1979 |pmid= 106884 |doi=10.1021/bi00575a016  }}
*{{cite journal  | vauthors=Fernandez HN, Hugli TE |title=Primary structural analysis of the polypeptide portion of human C5a anaphylatoxin. Polypeptide sequence determination and assignment of the oligosaccharide attachment site in C5a |journal=J. Biol. Chem. |volume=253 |issue= 19 |pages= 6955–64 |year= 1978 |doi=10.1016/S0021-9258(17)38013-4 |pmid= 690134 |doi-access=free }}
*{{cite journal  | author=DiScipio RG |title=Formation and structure of the C5b-7 complex of the lytic pathway of complement |journal=J. Biol. Chem. |volume=267 |issue= 24 |pages= 17087–94 |year= 1992 |doi=10.1016/S0021-9258(18)41897-2 |pmid= 1387399 |doi-access=free }}
*{{cite journal  | vauthors=Haviland DL, Haviland JC, Fleischer DT |title=Complete cDNA sequence of human complement pro-C5. Evidence of truncated transcripts derived from a single copy gene |journal=J. Immunol. |volume=146 |issue= 1 |pages= 362–8 |year= 1991 |doi=10.4049/jimmunol.146.1.362 |pmid= 1984448 |display-authors=etal|doi-access=free }}
*{{cite journal  | vauthors=Bohnsack JF, Mollison KW, Buko AM |title=Group B streptococci inactivate complement component C5a by enzymic cleavage at the C-terminus |journal=Biochem. J. |volume=273 |issue=  Pt 3|pages= 635–40 |year= 1991 |pmid= 1996961 |doi=  10.1042/bj2730635| pmc=1149811  |display-authors=etal}}
*{{cite journal  | vauthors=Lundwall AB, Wetsel RA, Kristensen T |title=Isolation and sequence analysis of a cDNA clone encoding the fifth complement component |journal=J. Biol. Chem. |volume=260 |issue= 4 |pages= 2108–12 |year= 1985 |doi=10.1016/S0021-9258(18)89523-0 |pmid= 2579066 |display-authors=etal|doi-access=free }}
*{{cite journal  | vauthors=Zuiderweg ER, Fesik SW |title=Heteronuclear three-dimensional NMR spectroscopy of the inflammatory protein C5a |journal=Biochemistry |volume=28 |issue= 6 |pages= 2387–91 |year= 1989 |pmid= 2730871 |doi=10.1021/bi00432a008  }}
*{{cite journal  | vauthors=Zuiderweg ER, Nettesheim DG, Mollison KW, Carter GW |title=Tertiary structure of human complement component C5a in solution from nuclear magnetic resonance data |journal=Biochemistry |volume=28 |issue= 1 |pages= 172–85 |year= 1989 |pmid= 2784981 |doi=10.1021/bi00427a025  }}
*{{cite journal  | vauthors=Haefliger JA, Tschopp J, Vial N, Jenne DE |title=Complete primary structure and functional characterization of the sixth component of the human complement system. Identification of the C5b-binding domain in complement C6 |journal=J. Biol. Chem. |volume=264 |issue= 30 |pages= 18041–51 |year= 1989 |doi=10.1016/S0021-9258(19)84676-8 |pmid= 2808363 |doi-access=free }}
*{{cite journal  | vauthors=Wetsel RA, Lemons RS, Le Beau MM |title=Molecular analysis of human complement component C5: localization of the structural gene to chromosome 9 |journal=Biochemistry |volume=27 |issue= 5 |pages= 1474–82 |year= 1988 |pmid= 3365401 |doi=10.1021/bi00405a012  |display-authors=etal}}
*{{cite journal  | vauthors=Zuiderweg ER, Mollison KW, Henkin J, Carter GW |title=Sequence-specific assignments in the 1H NMR spectrum of the human inflammatory protein C5a |journal=Biochemistry |volume=27 |issue= 10 |pages= 3568–80 |year= 1988 |pmid= 3408713 |doi=10.1021/bi00410a007  }}
*{{cite journal  | vauthors=Stewart JL, Kolb WP, Sodetz JM |title=Evidence that C5b recognizes and mediates C8 incorporation into the cytolytic complex of complement |journal=J. Immunol. |volume=139 |issue= 6 |pages= 1960–4 |year= 1987 |doi=10.4049/jimmunol.139.6.1960 |pmid= 3624872 |doi-access=free }}
*{{cite journal  | vauthors=Buhl AM, Osawa S, Johnson GL |title=Mitogen-activated protein kinase activation requires two signal inputs from the human anaphylatoxin C5a receptor |journal=J. Biol. Chem. |volume=270 |issue= 34 |pages= 19828–32 |year= 1995 |pmid= 7649993 |doi=10.1074/jbc.270.34.19828  |doi-access=free }}
*{{cite journal  | vauthors=Babkina IN, Seregin SV, Daniliuk NK |title=[Chemico-enzymatic synthesis, cloning and expression of a gene for an analog of human anaphylatoxin C5a] |journal=Bioorg. Khim. |volume=21 |issue= 5 |pages= 359–64 |year= 1995 |pmid= 7661861 |display-authors=etal}}
*{{cite journal  | vauthors=Wang X, Fleischer DT, Whitehead WT |title=Inherited human complement C5 deficiency. Nonsense mutations in exons 1 (Gln1 to Stop) and 36 (Arg1458 to Stop) and compound heterozygosity in three African-American families |journal=J. Immunol. |volume=154 |issue= 10 |pages= 5464–71 |year= 1995 |doi=10.4049/jimmunol.154.10.5464 |pmid= 7730648 |display-authors=etal|doi-access=free }}
*{{cite journal  | vauthors=Oppermann M, Götze O |title=Plasma clearance of the human C5a anaphylatoxin by binding to leucocyte C5a receptors |journal=Immunology |volume=82 |issue= 4 |pages= 516–21 |year= 1995 |pmid= 7835913 | pmc=1414921  }}
*{{cite journal  | vauthors=Süsal C, Kirschfink M, Kröpelin M |title=Complement activation by recombinant HIV-1 glycoprotein gp120 |journal=J. Immunol. |volume=152 |issue= 12 |pages= 6028–34 |year= 1994 |doi=10.4049/jimmunol.152.12.6028 |pmid= 7911492 |display-authors=etal|doi-access=free }}
*{{cite journal  | vauthors=Arribas J, Arizti P, Castaño JG |title=Antibodies against the C2 COOH-terminal region discriminate the active and latent forms of the multicatalytic proteinase complex |journal=J. Biol. Chem. |volume=269 |issue= 17 |pages= 12858–64 |year= 1994 |doi=10.1016/S0021-9258(18)99955-2 |pmid= 8175701 |doi-access=free }}
*{{cite journal  | vauthors=Süsal C, Kirschfink M, Kröpelin M |title=Identification of complement activation sites in human immunodeficiency virus type-1 glycoprotein gp120 |journal=Blood |volume=87 |issue= 6 |pages= 2329–36 |year= 1996 |pmid= 8630395 |doi=  10.1182/blood.V87.6.2329.bloodjournal8762329|display-authors=etal|doi-access=free }}
*{{cite journal  | vauthors=Ames RS, Li Y, Sarau HM |title=Molecular cloning and characterization of the human anaphylatoxin C3a receptor |journal=J. Biol. Chem. |volume=271 |issue= 34 |pages= 20231–4 |year= 1996 |pmid= 8702752 |doi=10.1074/jbc.271.34.20231  |display-authors=etal|doi-access=free }}
*{{cite journal | vauthors=Fredslund F, Laursen NS, Roversi P | title=Structure of and influence of a tick complement inhibitor on human complement component 5 | journal=Nat Immunol |volume= 9 |issue= 7 |pages= 753–60 |year= 2008 |pmid= 18536718 | doi=10.1038/ni.1625 | s2cid=205361576 |display-authors=etal}}
{{refend}}

==External links==
* {{MeshName|Complement+5}}

{{NLM content}}

{{PDB Gallery|geneid=727}}
{{Complement system}}

[[Category:Complement system]]

{{Gene-9-stub}}