Reactome | Complement factor I inactivates C3b

Complement factor I inactivates C3b

Stable Identifier

R-GGA-2132276

Type

Reaction [transition]

Species

Gallus gallus

Compartment

extracellular region

ReviewStatus

5/5

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Complement factor I (CFI) is a serine protease that inhibits the complement pathway by degrading extracellular C3b into inactive fragments iC3b and C3f. Factor H acts as cofactor of factor I proteolytic activity on C3b [Ross JD et al 1982; Masaki T et al 1992; Fukui A et al 2002; Nilsson SC et al 2010].

Predicted chicken CFI shows 51% amino acid sequence identity with its human counterpart. The chicken events of complement factor I activity have not been verified experimentally but are inferred from properties of the orthologous human proteins.

Literature References

PubMed ID	Title	Journal	Year
1386357	Factor I-dependent inactivation of human complement C4b of the classical pathway by C3b/C4b receptor (CR1, CD35) and membrane cofactor protein (MCP, CD46) Masaki, T, Matsumoto, M, Nakanishi, I, Yasuda, R, Seya, T	J Biochem	1992
12417021	Mapping of the sites responsible for factor I-cofactor activity for cleavage of C3b and C4b on human C4b-binding protein (C4bp) by deletion mutagenesis Fukui, A, Yuasa-Nakagawa, T, Murakami, Y, Funami, K, Kishi, N, Matsuda, T, Fujita, T, Seya, T, Nagasawa, S	J. Biochem.	2002
6214588	Generation of three different fragments of bound C3 with purified factor I or serum. I. Requirements for factor H vs CR1 cofactor activity Ross, GD, Lambris, JD, Cain, JA, Newman, SL	J Immunol	1982
20044478	Analysis of binding sites on complement factor I that are required for its activity Nilsson, SC, Nita, I, Månsson, L, Groeneveld, TW, Trouw, LA, Villoutreix, BO, Blom, AM	J. Biol. Chem.	2010