C2 - complement component 2 (within H-2S)

This gene encodes component C2 of the classical pathway of the complement system. The encoded protein undergoes proteolytic processing mediated by component C1 resulting in C2a and C2b fragments. C2a fragment, in turn, selectively cleaves components C3 and C5 of the complement system. Mice lacking the encoded protein are found to be more susceptible to bacterial infections. Mutations in the human homolog of this gene are associated with disorders such as systemic lupus erythematosus, Henoch-Schonlein purpura, or polymyositis. [provided by RefSeq, Mar 2015]