title: Molecular and functional characterization of peptidoglycan-recognition protein SC2 (PGRP-SC2) from Nile tilapia (Oreochromis niloticus) involved in the immune response to Streptococcus agalactiae.
abstract: PGRP-SC2, the member of PGRP family, plays an important role in regulation of innate immune response. In this paper, a PGRP-SC2 gene of Nile tilapia, Oreochromis niloticus (designated as On-PGRP-SC2) was cloned and its expression pattern under the infection of Streptococcus agalactiae was investigated. Sequence analysis showed main structural features required for amidase activity were detected in the deduced amino acid sequence of On-PGRP-SC2. In healthy tilapia, the On-PGRP-SC2 transcripts could be detected in all the examined tissues, with the most abundant expression in the muscle. When infected with S. agalactiae, there was a clear time-dependent expression pattern of On-PGRP-SC2 in the spleen, head kidney and brain. The assays for the amidase activity suggested that recombinant On-PGRP-SC2 protein had a Zn(2+)-dependent PGN-degrading activity. Moreover, our works showed that recombinant On-PGRP-SC2 protein could significantly reduce bacterial load in target organs attacked by S. agalactiae. These findings indicated that On-PGRP-SC2 may play important roles in the immune response to S. agalactiae in Nile tilapia.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; College of Fishery, Guangdong Ocean University, Zhanjiang 524025, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Gan
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Shannan
authors.initials: S
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Huo
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Baiye
authors.initials: B
authors.lastname: Ruan
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Zubair Ahmed
authors.initials: ZA
authors.lastname: Laghari
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Fishery, Guangdong Ocean University, Zhanjiang 524025, China. Electronic address: fishdis@163.com.
authors.forename: Yishan
authors.initials: Y
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: pinnie@ihb.ac.cn.
authors.forename: Pin
authors.initials: P
authors.lastname: Nie
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D023681:Cichlids / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007113:Immunity, Innate / Q000235:genetics; D008968:Molecular Conformation; D009928:Organ Specificity; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary; D013290:Streptococcal Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D013292:Streptococcus agalactiae / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D029941:Fish Proteins; D012333:RNA, Messenger; C118897:peptidoglycan recognition protein
keywords: Amidase activity; Antimicrobial effect; Oreochromis niloticus; Peptidoglycan-recognition protein; Streptococcus agalactiae