title: Sulfide exposure results in enhanced sqr transcription through upregulating the expression and activation of HSF1 in echiuran worm Urechis unicinctus.
abstract: Sulfide is a natural, widely distributed, poisonous substance. Sulfide: quinone oxidoreductase (SQR) is responsible for the initial oxidation of sulfide in mitochondria. To study transcriptional regulation of sqr after sulfide exposure, a 2.6-kb sqr upstream sequence from echiuran worm Urechis unicinctus was cloned by genome walking. Bioinformatics analysis showed 3 heat shock elements (HSEs) in proximal promoter region of the sqr upstream sequence. Moreover, an Hsf1 cDNA in U. unicinctus (UuHsf1) was isolated with a full-length sequence of 2334 bp and its polyclonal antibody was prepared using U. unicinctus HSF1 (UuHSF1) expressed prokaryotically with whole sequence of its open reading frame (ORF). In vivo ChIP and in vitro EMSA assays revealed UuHSF1 could interact with the sqr proximal promoter region. Transient transfection and mutation assays indicated that UuHSF1 bound specifically to HSE (-155bp to -143bp) and enhanced the transcription of sqr. Furthermore, sulfide treatment experiments demonstrated that sulfide could increase the expression of HSF1 protein, and induce trimerization of the protein which binds to HSEs and then activate sqr transcription. Quantitative real-time PCR analysis revealed sqr mRNA level increased significantly after U. unicinctus was exposed to sulfide for 6h, which corresponded to content changes of both trimeric HSF1 and HSF1-HSE complex. We concluded that UuHSF1 is a transcription factor of sqr and sulfide could induce sqr transcription by upregulating the expression and activation of HSF1 in U. unicinctus exposed to sulfide.
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Liu
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China. Electronic address: zzfp107@ouc.edu.cn.
authors.forename: Zhifeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Ma
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Xueyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Di
authors.initials: D
authors.lastname: Zhou
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Gao
authors.affiliation: Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Yajiao
authors.initials: Y
authors.lastname: Bai
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004781:Environmental Exposure / Q000032:analysis*; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response / Q000187:drug effects / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D011077:Polychaeta / Q000187:drug effects / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D011808:Quinone Reductases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013440:Sulfides / Q000633:toxicity*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D015854:Up-Regulation / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D000076249:Heat Shock Transcription Factors; D012333:RNA, Messenger; D013440:Sulfides; D014157:Transcription Factors; D014874:Water Pollutants, Chemical; D011808:Quinone Reductases; C073412:sulfide quinone reductase
keywords: HSF1; Promoter; Sulfide exposure; Sulfidequinone oxidoreductase (SQR); Transcription regulation; Urechis unicinctus