Identification and cloning of a selenium-dependent glutathione peroxidase from tiger shrimp, Penaeus monodon, and its transcription following pathogen infection and related to the molt stages.

Abstract

Complementary (c)DNA encoding glutathione peroxidase (GPx) messenger (m)RNA of the tiger shrimp Penaeus monodon was obtained from haemocytes by a reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) method. The 1321-bp cDNA contained an open reading frame (ORF) of 564bp, a 69-bp 5'-untranslated region (UTR), and a 688-bp 3'-UTR containing a poly A tail and a conserved selenocysteine insertion sequence (SECIS) element. The molecular mass of the deduced amino acid (aa) sequence (188 aa) was 21.05kDa long with an estimated pI of 7.68. It contains a putative selenocysteine residue which is encoded by the unusual stop codon, (190)TGA(192), and forms the active site with residues Glu(75) and Trp(143). Comparison of amino acid sequences showed that tiger shrimp GPx is more closely related to vertebrate GPx1, in accordance with those in Litopenaeus vannamei and Macrobrachium rosenbergii. GPx cDNA was synthesised in lymphoid organ, gills, heart, haemocytes, the hepatopancreas, muscles, and intestines. After injected with either Photobacterium damsela or white spot syndrome virus (WSSV), the respiratory bursts of shrimp significantly increased in order to kill the pathogen, and induced increases in the activities of superoxide dismutase and GPx, and regulation in the expression of cloned GPx mRNA to protect cells against damage from oxidation. The GPx expression significantly increased at stage D(0/1), and then gradually decreased until stage C suggesting that the cloned GPx might play a role in the molt regulation of shrimp.

• Authors: Kuan-Fu Liu, Maw-Sheng Yeh, Guang-Hsiung Kou, Winton Cheng, Chu-Fang Lo
• Journal: Developmental and comparative immunology (Dev Comp Immunol) Vol. 34 Issue 9 Pg. 935-44 (Sep 2010) ISSN: 1879-0089 [Electronic] United States
• PMID: 20399225 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2010 Elsevier Ltd. All rights reserved.

Chemical References

• Selenocysteine
• Glutathione Peroxidase

Topics

• Amino Acid Sequence
• Animals
• Cloning, Molecular
• DNA Virus Infections (enzymology, genetics, immunology)
• Gene Expression Profiling
• Gene Expression Regulation, Enzymologic
• Glutathione Peroxidase (genetics, immunology, isolation & purification, metabolism)
• Gram-Negative Bacterial Infections (enzymology, genetics, immunology)
• Hemocytes (immunology, metabolism, pathology)
• Molecular Sequence Data
• Molting (genetics)
• Penaeidae
• Photobacterium (immunology, pathogenicity)
• Phylogeny
• Respiratory Burst
• Selenocysteine (genetics, metabolism)
• Transcriptional Activation
• White spot syndrome virus 1 (immunology, pathogenicity)