Activation of C3 and C5

Stable Identifier
R-HSA-174577
DOI
10.3180/R-HSA-174577.6
Type
Pathway
Species
Homo sapiens
Compartment
extracellular region, plasma membrane
ReviewStatus
5/5
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Activation of C3 and C5
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The 3 pathways of complement activation converge on the cleavage of C3 by C3 convertases. C3 convertase cleaves C3 into C3a and C3b - a central step of complement activation. C3a remains in the fluid phase and acts as an anaphylatoxin, whereas C3b can form additional C3 convertases hastening the production of C3b. Besides, C3b binds to C3 convertases to form C5 convertase, which can act as an opsonin, or is degraded into fragments which cannot form an active convertase.
Literature References
PubMed ID Title Journal Year
15199963 The lectin-complement pathway--its role in innate immunity and evolution

Fujita, T, Matsushita, M, Endo, Y

Immunol Rev 2004
458145 The alternative pathway C3/C5 convertase: chemical basis of factor B activation

Lesavre, PH, Hugli, TE, Esser, AF, Muller-Eberhard, HJ

J Immunol 1979
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Events
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Event Information
Go Biological Process
complement activation (0006956)
Orthologous Events
Activation of C3 and C5 (Bos taurus)
Activation of C3 and C5 (Canis familiaris)
Activation of C3 and C5 (Danio rerio)
Activation of C3 and C5 (Gallus gallus)
Activation of C3 and C5 (Mus musculus)
Activation of C3 and C5 (Rattus norvegicus)
Activation of C3 and C5 (Sus scrofa)
Activation of C3 and C5 (Xenopus tropicalis)
Cross References
BioModels Database
Authored
de Bono, B  (2004-08-04)
Reviewed
D'Eustachio, P  (2006-07-04)
Matthews, L  (2025-08-22)
Created
de Bono, B  (2006-02-20)
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