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

Locations in the PathwayBrowser

Expand all

General

SBML | | PDF

SVG | | PPTX | SBGN

Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

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) Matsumoto, M, Yasuda, R, Nakanishi, I, Seya, T, Masaki, 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, Matsuda, T, Nagasawa, S, Funami, K, Murakami, Y, Kishi, N, Yuasa-Nakagawa, T, Seya, T, Fujita, T	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, Newman, SL, Lambris, JD, Cain, JA	J Immunol	1982
20044478	Analysis of binding sites on complement factor I that are required for its activity Blom, AM, Månsson, L, Groeneveld, TW, Nilsson, SC, Villoutreix, BO, Nita, I, Trouw, LA	J. Biol. Chem.	2010