A potential antioxidant enzyme belonging to the atypical 2-Cys peroxiredoxin subfamily characterized from rock bream, Oplegnathus fasciatus.
Peroxiredoxins (Prxs), a diverse family of antioxidant enzymes, exert their antioxidant function through which different peroxide species are detoxified. This study describes both structural and functional characterization of a mitochondrial Prx identified in rock bream, Oplegnathus fasciatus (RbPrx5). The ORF (573 bp) of RbPrx5 encoded a protein of 190 amino acids (20 kDa) containing a putative mitochondrial targeting sequence (residues 1-20) and a thioredoxin-2 motif (residues 31-190) and three conserved Cys residues. Homology assessment and phylogenetic analysis clearly disclosed relatively higher amino acid sequence similarities and a closer evolutionary position of RbPrx5 with those of other teleost homologs. The ORF of RbPrx5 was distributed among six exons as found in other vertebrates, but it possessed an additional exon in its 5'-UTR. In silico examination of RbPrx5 gene's putative promoter region revealed the presence of several cis-elements which may be important in its transcriptional regulation. Constitutive expression of RbPrx5 was detected in eleven tissues with the highest level in the heart. Modulation of RbPrx5 transcription was evidenced from varying mRNA levels in head kidney post in vivo LPS-, poly I:C-, Edwardsiella tarda bacterial- and rock bream iridoviral-challenges. The antioxidant function of RbPrx5 was investigated using recombinant RbPrx5 protein. Results of an in vitro mixed-function oxidase assay demonstrated a dose-dependent inhibition of DNA damage by rRbPrx5. A H2O2 tolerance assay showed that in vivo overexpression of rRbPrx5 increased the bacterial survival under H2O2-mediated oxidative stress condition. These findings provide an overall insight into the structural, expressional and functional aspects of RbPrx5.
Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
Kasthuri
K
Saranya Revathy
Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
Navaneethaiyer
N
Umasuthan
Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
Ilson
I
Whang
Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
Hyung-Bok
HB
Jung
Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
Bong-Soo
BS
Lim
Biotechnology Research Division, National Fisheries Research and Development Institute, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan 619-705, Republic of Korea.
Bo-Hye
BH
Nam
Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea. Electronic address: jehee@jejunu.ac.kr.
Jehee
J
Lee
D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D004249:DNA Damage; D004926:Escherichia coli / Q000502:physiology; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects; D023281:Genomics; D006861:Hydrogen Peroxide / Q000494:pharmacology; D017994:Iridovirus / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010473:Perciformes / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology / Q000821:virology; D054464:Peroxiredoxins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000975:Antioxidants; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D011994:Recombinant Proteins; D006861:Hydrogen Peroxide; D054464:Peroxiredoxins; D011070:Poly I-C
Antioxidant protection; Gene structure; Mitochondrial peroxiredoxin 5 (Prx5); Oxidative stress; mRNA expression profiling