Reactome | Conversion of C2 into C2a and C2b

Conversion of C2 into C2a and C2b

Stable Identifier

R-HSA-166792

Type

Reaction [transition]

Species

Homo sapiens

Compartment

extracellular region, plasma membrane

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

C2 is cleaved into the large C2a and the small C2b fragment. This irreversible, extracellular reaction can be catalyzed by activated MBL, generated through the lectin pathway of complement activation (Vorup-Jensen et al. 2000), and by activated C1, generated through the classical pathway (Nasagawa and Stroud 1977). N.B. Early literature refers to the larger fragment of C2 as C2a. However, complement scientists decided that the smaller of all C fragments should be designated with an 'a', the larger with a 'b', changing the nomenclature for C2. For this reason recent literature may refer to the larger C2 fragment as C2b, and the classical C3 convertase as C4bC2b. Throughout this pathway, Reactome uses the current (Feb 2012) Uniprot names which adhere to the original naming practice.

Literature References

PubMed ID	Title	Journal	Year
6019133	Formation and functional significance of a molecular complex derived from the second and the fourth component of human complement Muller-Eberhard, HJ, Polley, MJ, Calcott, MA	J Exp Med	1967
10925294	Distinct pathways of mannan-binding lectin (MBL)- and C1-complex autoactivation revealed by reconstitution of MBL with recombinant MBL-associated serine protease-2 Vorup-Jensen, T, Petersen, SV, Hansen, AG, Poulsen, K, Schwaeble, W, Sim, RB, Reid, KB, Davis, SJ, Thiel, S, Jensenius, JC	J Immunol	2000
70787	Cleavage of C2 by C1s into the antigenically distinct fragments C2a and C2b: demonstration of binding of C2b to C4b Nagasawa, S, Stroud, RM	Proc Natl Acad Sci U S A	1977
12396008	The biological functions of MBL-associated serine proteases (MASPs) Hajela, K, Kojima, M, Ambrus, G, Wong, KH, Moffatt, BE, Ferluga, J, Hajela, S, Gal, P, Sim, RB	Immunobiology	2002