Gene:
properdin P factor, complement
Gene ID:
196227
Symbol:
PFC
Species:
1000
Description:
Properdin (factor P) is a plasma protein that is active in the alternative complement pathway of the innate immune system. It is a positive regulatory factor that binds to many microbial surfaces to stabilize the C3b,Bb convertase. The C3b,Bb convertase then rapidly cleaves more C3 to C3b, which acts either as an opsonin or to reinitiate the pathway in an amplification loop that proceeds on the bacterial cell, but not on the host cell (Janeway et al., 2001). In the alternative pathway, C3 is thus activated through factor B, factor D, and properdin P, under the control of factors I and H (Fearon and Austen, 1980). Deficiency of properdin is associated in particular with a heightened susceptibility to Neisseria species (Janeway et al., 2001).[supplied by OMIM]