Complement factor B is a protein that in humans is encoded by the CFBgene.
This gene encodes complement factor B, a component of the alternative pathway of complement activation. Factor B circulates in the blood as a single chain polypeptide. Upon activation of the alternative pathway, it is cleaved by complement factor D yielding the noncatalytic chain Ba and the catalytic subunit Bb. The active subunit Bb is a serine protease that associates with C3b to form the alternative pathway C3 convertase. Bb is involved in the proliferation of preactivated B lymphocytes, while Ba inhibits their proliferation. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. This cluster includes several genes involved in regulation of the immune reaction. The polyadenylation site of this gene is 421 bp from the 5' end of the gene for complement component 2.
Arnason A, Larsen B, Marshall WH, et al. (1977). "Very close linkage between HLA-B and Bf inferred from allelic association". Nature268 (5620): 527–8. doi:10.1038/268527a0. PMID889587.
Barnum SR, Ishii Y, Agrawal A, Volanakis JE (1992). "Production and interferon-gamma-mediated regulation of complement component C2 and factors B and D by the astroglioma cell line U105-MG". Biochem. J. 287. ( Pt 2): 595–601. PMC1133207. PMID1445220.
Yancey KB, Overholser O, Domloge-Hultsch N, et al. (1992). "Human keratinocytes and A-431 cells synthesize and secrete factor B, the major zymogen protease of the alternative complement pathway". J. Invest. Dermatol.98 (3): 379–83. doi:10.1111/1523-1747.ep12499812. PMID1545147.
Niemann MA, Bhown AS, Miller EJ (1991). "The principal site of glycation of human complement factor B". Biochem. J. 274. ( Pt 2): 473–80. PMC1150163. PMID2006911.
Davrinche C, Abbal M, Clerc A (1991). "Molecular characterization of human complement factor B subtypes". Immunogenetics32 (5): 309–12. PMID2249879.
Farries TC, Lachmann PJ, Harrison RA (1988). "Analysis of the interaction between properdin and factor B, components of the alternative-pathway C3 convertase of complement". Biochem. J.253 (3): 667–75. PMC1149358. PMID3140783.
Wu LC, Morley BJ, Campbell RD (1987). "Cell-specific expression of the human complement protein factor B gene: evidence for the role of two distinct 5'-flanking elements". Cell48 (2): 331–42. doi:10.1016/0092-8674(87)90436-3. PMID3643061.
Morley BJ, Campbell RD (1984). "Internal homologies of the Ba fragment from human complement component Factor B, a class III MHC antigen". EMBO J.3 (1): 153–7. PMC557312. PMID6323161.
Christie DL, Gagnon J (1983). "Amino acid sequence of the Bb fragment from complement Factor B. Sequence of the major cyanogen bromide-cleavage peptide (CB-II) and completion of the sequence of the Bb fragment". Biochem. J.209 (1): 61–70. PMC1154056. PMID6342610.
Mole JE, Anderson JK, Davison EA, Woods DE (1984). "Complete primary structure for the zymogen of human complement factor B". J. Biol. Chem.259 (6): 3407–12. PMID6546754.
Woods DE, Markham AF, Ricker AT, et al. (1982). "Isolation of cDNA clones for the human complement protein factor B, a class III major histocompatibility complex gene product". Proc. Natl. Acad. Sci. U.S.A.79 (18): 5661–5. doi:10.1073/pnas.79.18.5661. PMC346964. PMID6957884.