title: Molecular cloning, characterization and expression analysis of the PKZ gene in rare minnow Gobiocypris rarus.
abstract: Double-stranded RNA-activated protein kinase (PKR) plays an important role in interferon-induced antiviral responses, and is also involved in intracellular signaling pathways, including the apoptosis, proliferation, and transcription pathways. In the present study, a PKR-like gene was cloned and characterized from rare minnow Gobiocypris rarus. The full length of the rare minnow PKR-like (GrPKZ) cDNA is 1946 bp in length and encodes a polypeptide of 503 amino acids with an estimated molecular mass of 57,355 Da and a predicted isoelectric point of 5.83. Analysis of the deduced amino acid sequence indicated that the mature peptide contains two Zalpha domains and one S_TKc domain, and is most similar to the crucian carp (Carassius auratus) PKR-like amino acid sequence with an identity of 77%. Quantitative RT-PCR analysis showed that GrPKZ mRNA expression is at low levels in gill, heart, intestine, kidney, liver, muscle and spleen tissues in healthy animals and up-regulated by viruses and bacteria. After being infected by grass carp reovirus, GrPKZ expression was up-regulated from 24h post-injection and lasted until the fish became moribund (P<0.05). Following infection with Aeromonas hydrophila, GrPKZ transcripts were induced at 24h post-injection (P<0.05) and returned to control levels at 120 h post-injection. These data imply that GrPKZ is involved in antiviral defense and Toll-like receptor 4 signaling pathway in bacterial infection.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Su
authors.forename: Zuoyan
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wang
mesh_terms: D016980:Aeromonas hydrophila / Q000276:immunology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003530:Cyprinidae / Q000235:genetics* / Q000382:microbiology / Q000821:virology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D016905:Gram-Negative Bacterial Infections / Q000276:immunology / Q000662:veterinary; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger; D012087:Reoviridae / Q000276:immunology; D012088:Reoviridae Infections / Q000276:immunology; D016415:Sequence Alignment; D013997:Time Factors; D019892:eIF-2 Kinase / Q000737:chemistry / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D019892:eIF-2 Kinase