Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp NJ-18

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	Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp NJ-18
	Wang, Xin; Xu, Xudong
刊名	GENE
	2012-06-10
卷号	501 期号:1 页码:17-23
关键词	Thioredoxin-dependent GPX Induced expression Chlorella Synechocystis
ISSN号	0378-1119
通讯作者	Xu, XD (reprint author), Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Hubei, Peoples R China.
中文摘要	Photosynthetic organisms often encounter oxidative stresses due to changes of environmental conditions. In this study, two glutathione peroxidase (GPX) homologous genes, namely NJ-18Gpx1 and NJ-18Gpx2, were identified in Chlorella sp. NJ-18, a single-celled green alga. The two NJ-18Gpx genes can produce 2 or 3 transcript variants by alternative splicing, predicted to encode 4 non-selenium GPX proteins (NS-GPX). Expression of the two genes was analyzed by quantitative RT-PCR in Chlorella sp. NJ-18 exposed to various treatments known to generate reactive oxygen species. Neutral red, a singlet oxygen-generating photosensitizer, significantly increased the expression of NJ-18Gpx1 within 5 h. Exposure of algal culture to UV-B for 3 h caused up-regulation of mRNA levels of NJ-18Gpx1 and NJ-18Gpx2 by 4- and 50-folds, respectively. Similar to CrGPX5 and CrGPX3 in Chlamydomonas reinhardtii, purified recombinant NJ-18GPXs showed activities of thioredoxin-dependent peroxidases that catalyze the reduction of hydrogen peroxide and organic hydroperoxides. The V-max values for NJ-18GPX1 toward different peroxides were approximately 10-fold higher than those for NJ-18GPX2. In addition, overexpression of NJ-18Gpx1 in Synechocystis sp. PCC 6803, a cyanobacterium, enhanced its tolerance to neutral red and H2O2. These results indicate that NJ-18GPXs can act as efficient peroxide scavengers protecting cells from oxidative damages in Chlorella. (C) 2012 Elsevier B.V. All rights reserved.
英文摘要	Photosynthetic organisms often encounter oxidative stresses due to changes of environmental conditions. In this study, two glutathione peroxidase (GPX) homologous genes, namely NJ-18Gpx1 and NJ-18Gpx2, were identified in Chlorella sp. NJ-18, a single-celled green alga. The two NJ-18Gpx genes can produce 2 or 3 transcript variants by alternative splicing, predicted to encode 4 non-selenium GPX proteins (NS-GPX). Expression of the two genes was analyzed by quantitative RT-PCR in Chlorella sp. NJ-18 exposed to various treatments known to generate reactive oxygen species. Neutral red, a singlet oxygen-generating photosensitizer, significantly increased the expression of NJ-18Gpx1 within 5 h. Exposure of algal culture to UV-B for 3 h caused up-regulation of mRNA levels of NJ-18Gpx1 and NJ-18Gpx2 by 4- and 50-folds, respectively. Similar to CrGPX5 and CrGPX3 in Chlamydomonas reinhardtii, purified recombinant NJ-18GPXs showed activities of thioredoxin-dependent peroxidases that catalyze the reduction of hydrogen peroxide and organic hydroperoxides. The V-max values for NJ-18GPX1 toward different peroxides were approximately 10-fold higher than those for NJ-18GPX2. In addition, overexpression of NJ-18Gpx1 in Synechocystis sp. PCC 6803, a cyanobacterium, enhanced its tolerance to neutral red and H2O2. These results indicate that NJ-18GPXs can act as efficient peroxide scavengers protecting cells from oxidative damages in Chlorella. (C) 2012 Elsevier B.V. All rights reserved.
WOS标题词	Science & Technology ; Life Sciences & Biomedicine
类目[WOS]	Genetics & Heredity
研究领域[WOS]	Genetics & Heredity
关键词[WOS]	SYNECHOCYSTIS SP PCC-6803 ; CHLAMYDOMONAS-REINHARDTII ; OXIDATIVE STRESS ; ARABIDOPSIS-THALIANA ; ANTIOXIDANT ENZYMES ; ABIOTIC STRESSES ; REDOX-TRANSDUCER ; SINGLET OXYGEN ; FAMILY ; PEROXIREDOXIN
收录类别	SCI
资助信息	Chinese Academy of Sciences[KSCX2-YW-G-060, KSCX2-SW-332]
语种	英语
WOS记录号	WOS:000304584000003
公开日期	2012-09-25
内容类型	期刊论文
源URL	[http://ir.ihb.ac.cn/handle/342005/17041]
专题	水生生物研究所_藻类生物学及应用研究中心_期刊论文
作者单位	Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Hubei, Peoples R China
推荐引用方式 GB/T 7714	Wang, Xin,Xu, Xudong. Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp NJ-18[J]. GENE,2012,501(1):17-23.
APA	Wang, Xin,&Xu, Xudong.(2012).Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp NJ-18.GENE,501(1),17-23.
MLA	Wang, Xin,et al."Molecular cloning and functional analyses of glutathione peroxidase homologous genes from Chlorella sp NJ-18".GENE 501.1(2012):17-23.