title: Cloning and molecular characterization of two complement Bf/C2 genes in large yellow croaker (Pseudosciaena crocea).
abstract: Complement components factor B and C2 are two crucial proteases in the alternative pathway (AP) and classical pathway (CP). Two Bf/C2 cDNAs, LycBf/C2A and LycBf/C2B were isolated from the large yellow croaker (Pseudosciaena crocea) by suppression subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE). Through sequence alignment and computer 3D modeling analysis, we found that both of the deduced proteins contain three complement control protein (CCP) modules, a von Willebrand factor A (vWFA) domain, and one serine protease (SP) domain. Both structural analysis and phylogenetic analyses suggested that LycBf/C2A is more like human factor B than human C2 while LycBf/C2B is more human C2-like. After that, RT-PCR assay showed that LycBf/C2A and LycBf/C2B were mostly expressed in liver, albeit detectable in other tissues. Finally, after being infected with attenuated live Vibrio anguillarum strain, the expression level of LycBf/C2A and LycBf/C2B were found remarkably up-regulated in liver, spleen and kidney, indicating that the two complement factors play a pivotal role in the immune response to bacterial challenge in large yellow croaker.
authors.affiliation: State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Haizhen
authors.initials: H
authors.lastname: Wu
authors.forename: Hongyan
authors.initials: H
authors.lastname: Xu
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.forename: Xiao
authors.initials: X
authors.lastname: Zhang
authors.forename: Kangmei
authors.initials: K
authors.lastname: Chang
authors.forename: Yuanxing
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003175:Complement C2 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011415:Complement Factor B / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005393:Fish Diseases / Q000276:immunology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014733:Vibrio / Q000502:physiology; D014735:Vibrio Infections / Q000276:immunology
chemical_list: D003175:Complement C2; D011415:Complement Factor B