title: sghC1q, a novel C1q family member from half-smooth tongue sole (Cynoglossus semilaevis): identification, expression and analysis of antibacterial and antiviral activities.
abstract: The C1q family includes many proteins that contain a globular (gC1q) domain, and this family is widely conserved from bacteria to mammals. The family is divided into three subgroups: C1q, C1q-like and ghC1q. In this study, a novel C1q family member, sghC1q, was cloned and identified from Cynoglossus semilaevis (named CssghC1q). The full-length CssghC1q cDNA spans 905 bp, including an open reading frame (ORF) of 768 bp, a 5'-untranslated region (UTR) of 25 bp and a 3'-UTR of 112 bp. The ORF encodes a putative protein of 255 amino acids (aa) with a deduced molecular weight of 28 kDa. The predicted protein contains a signal peptide (aa 1-19), a coiled-coil region (aa 61-102) and a globular C1q (gC1q) domain (aa 117-255). Protein sequence alignment indicated that the C-terminus of CssghC1q is highly conserved across several species. Phylogenetic analysis indicated that CssghC1q is most closely related to Maylandia zebra C1q-like-2-like. The CssghC1q genomic sequence spanned 1562 bp, with three exons and two introns. CssghC1q is constitutively expressed in all evaluated tissues, with the highest expression in the liver and the weakest in the heart. After a challenge with Vibrio anguillarum, CssghC1q transcript levels exhibited distinct time-dependent response patterns in the blood, head kidney, skin, spleen, intestine and liver. Recombinant CssghC1q protein exhibited antimicrobial activities against Gram-negative bacteria, Gram-positive bacteria and viruses. The minimum inhibitory concentration (MIC) values against Vibrio harveyi, Vibrio anguillarum, Pseudomonas aeruginosa and Staphylococcus aureus were 0.043 mg/mL, 0.087 mg/mL, 0.174 mg/mL and 0.025 mg/mL, respectively. A low concentration (0.06 mg/mL) of CssghC1q showed significant antiviral activity in vitro against nervous necrosis virus (NNV). These results suggest that CssghC1q plays a vital role in immune defense against bacteria and viruses.
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Xiang
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Henan Normal University, Xinxiang 453000, China.
authors.forename: Tianzi
authors.initials: T
authors.lastname: Wang
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Guangye
authors.initials: G
authors.lastname: Gong
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China; College of Fisheries and Life Science, Henan Normal University, Xinxiang 453000, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
authors.forename: Xihong
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Lab for Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao 266071, China. Electronic address: shazx@ysfri.ac.cn.
authors.forename: Zhenxia
authors.initials: Z
authors.lastname: Sha
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000276:immunology*; D000998:Antiviral Agents / Q000276:immunology*; D001483:Base Sequence; D003001:Cloning, Molecular; D015922:Complement C1q / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology*; D017124:Conserved Sequence; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology / Q000821:virology; D005412:Flatfishes; D020869:Gene Expression Profiling; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D030381:Nodaviridae / Q000276:immunology; D011552:Pseudomonas Infections / Q000276:immunology / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000276:immunology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000276:immunology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000276:immunology; D014733:Vibrio / Q000276:immunology; D014735:Vibrio Infections / Q000276:immunology / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D015922:Complement C1q
keywords: Antibacterial and antiviral activity; Cynoglossus semilaevis; Expression profile; sghC1q