title: Identification and characterization of Rab7 from orange-spotted grouper, Epinephelus coioides.
abstract: Rab7 is a small GTPase that regulates vesicular traffic from early to late endosomal stages of the endocytic pathway. During the virus-host co-evolution, host Rab7 was also exploited by virus to complete their life cycle. To date, however, the roles of fish Rab7 in virus infection remained largely unknown. Here, we cloned and characterized a Rab7 gene from grouper, Epinephelus coioides (Ec-Rab7). The full-length Ec-Rab7 cDNA was composed of 1182 bp and encoded a polypeptide of 207 amino acids which shared 99% identity with that from Anoplopoma fimbria or Oreochromis niloticus. Ec-Rab7 contained five conserved domains of Rab GTPase family including GTP-binding or GTPase regions as well as an effector site. RT-PCR analysis revealed that Ec-Rab7 ubiquitously expressed in all detected tissues and its transcript in spleen was up-regulated after challenge with Singapore grouper iridovirus (SGIV). Subcellular localization analysis revealed that Ec-Rab7 was distributed in the cytoplasm as spots and mostly colocalized with lysosomes. Notably, the ectopic expressed Ec-Rab7 partly aggregated into the viral factories in cells infected by SGIV. Furthermore, overexpression of Ec-Rab7 accelerated the occurrence of cytopathic effect (CPE) induced by SGIV infection and promoted viral gene transcription. In addition, far western blotting assay revealed that Ec-Rab7 might interact with viral proteins, including SGIV VP69 and VP101. Taken together, our data suggested that Ec-Rab7 might be potentially involved in SGIV replication.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Fu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.
authors.forename: Youhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Jia
authors.initials: J
authors.lastname: Cai
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China; University of Chinese Academy of Sciences, Beijing, PR China.
authors.forename: Shina
authors.initials: S
authors.lastname: Wei
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China.
authors.forename: Zhengliang
authors.initials: Z
authors.lastname: Ouyang
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, 135 West Xingang Road, Guangzhou 510275, PR China.
authors.forename: Fuzhou
authors.initials: F
authors.lastname: Ye
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: huangxh@scsio.ac.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Huang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: qinqw@scsio.ac.cn.
authors.forename: Qiwei
authors.initials: Q
authors.lastname: Qin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western / Q000662:veterinary; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004266:DNA Virus Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D005393:Fish Diseases / Q000276:immunology / Q000821:virology*; D017994:Iridovirus / Q000276:immunology*; D008969:Molecular Sequence Data; D010473:Perciformes; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014779:Virus Replication / Q000276:immunology; D020691:rab GTP-Binding Proteins / Q000235:genetics* / Q000276:immunology; D000090802:rab7 GTP-Binding Proteins
chemical_list: D000090802:rab7 GTP-Binding Proteins; D004247:DNA; D020691:rab GTP-Binding Proteins
keywords: Epinephelus coioides; Lysosome; Rab7; Singapore grouper iridovirus (SGIV); Virus replication