title: Hepatocyte Nuclear Factor 4α (HNF4α) Is a Transcription Factor of Vertebrate Fatty Acyl Desaturase Gene as Identified in Marine Teleost Siganus canaliculatus.
abstract: Rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the capability of biosynthesizing long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors, and to possess a Δ4 fatty acyl desaturase (Δ4 Fad) which was the first report in vertebrates, and is a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in teleosts. In order to understand regulatory mechanisms of transcription of Δ4 Fad, the gene promoter was cloned and characterized in the present study. An upstream sequence of 1859 bp from the initiation codon ATG was cloned as the promoter candidate. On the basis of bioinformatic analysis, several binding sites of transcription factors (TF) including GATA binding protein 2 (GATA-2), CCAAT enhancer binding protein (C/EBP), nuclear factor 1 (NF-1), nuclear factor Y (NF-Y), hepatocyte nuclear factor 4α (HNF4α) and sterol regulatory element (SRE), were identified in the promoter by site-directed mutation and functional assays. HNF4α and NF-1 were confirmed to interact with the core promoter of Δ4 Fad by gel shift assay and mass spectrometry. Moreover, over-expression of HNF4α increased promoter activity in HEK 293T cells and mRNA level of Δ4 Fad in rabbitfish primary hepatocytes, respectively. The results indicated that HNF4α is a TF of rabbitfish Δ4 Fad. To our knowledge, this is the first report on promoter structure of a Δ4 Fad, and also the first demonstration of HNF4α as a TF of vertebrate Fad gene involved in transcription regulation of LC-PUFA biosynthesis.
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Yewei
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Junliang
authors.initials: J
authors.lastname: Chen
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Qinghao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Cuihong
authors.initials: C
authors.lastname: You
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK94LA, Scotland, United Kingdom.
authors.forename: Óscar
authors.initials: Ó
authors.lastname: Monroig
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling, FK94LA, Scotland, United Kingdom.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Tocher
authors.affiliation: Marine Biology Institute & Guangdong Provincial Key Laboratory of Marine Biotechnology, Shantou University, Shantou, 515063, Guangdong, China.
authors.forename: Yuanyou
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D004247:DNA / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D004798:Enzymes / Q000235:genetics*; D005399:Fishes / Q000378:metabolism*; D017930:Genes, Reporter; D051557:Hepatocyte Nuclear Factor 4 / Q000378:metabolism*; D013058:Mass Spectrometry; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D004798:Enzymes; D051557:Hepatocyte Nuclear Factor 4; D009687:Nuclear Proteins; D004247:DNA