Dataset Information

Regulation of FADS2 transcription by SREBP-1 and PPAR-? influences LC-PUFA biosynthesis in fish.

ABSTRACT: The present study was conducted to explore the mechanisms leading to differences among fishes in the ability to biosynthesize long-chain polyunsaturated fatty acids (LC-PUFAs). Replacement of fish oil with vegetable oil caused varied degrees of increase in 18-carbon fatty acid content and decrease in n-3 LC-PUFA content in the muscle and liver of rainbow trout (Oncorhynchus mykiss), Japanese seabass (Lateolabrax japonicus) and large yellow croaker (Larimichthys crocea), suggesting that these fishes have differing abilities to biosynthesize LC-PUFAs. Fish oil replacement also led to significantly up-regulated expression of FADS2 and SREBP-1 but different responses of the two PPAR-? homologues in the livers of these three fishes. An in vitro experiment indicated that the basic transcription activity of the FADS2 promoter was significantly higher in rainbow trout than in Japanese seabass or large yellow croaker, which was consistent with their LC-PUFA biosynthetic abilities. In addition, SREBP-1 and PPAR-? up-regulated FADS2 promoter activity. These regulatory effects varied considerably between SREBP-1 and PPAR-?, as well as among the three fishes. Taken together, the differences in regulatory activities of the two transcription factors targeting FADS2 may be responsible for the different LC-PUFA biosynthetic abilities in these three fishes that have adapted to different ambient salinity.

SUBMITTER: Dong X

PROVIDER: S-EPMC5220380 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish.

Dong Xiaojing X Tan Peng P Cai Zuonan Z Xu Hanlin H Li Jingqi J Ren Wei W Xu Houguo H Zuo Rantao R Zhou Jianfeng J Mai Kangsen K Ai Qinghui Q

Scientific reports 20170109

The present study was conducted to explore the mechanisms leading to differences among fishes in the ability to biosynthesize long-chain polyunsaturated fatty acids (LC-PUFAs). Replacement of fish oil with vegetable oil caused varied degrees of increase in 18-carbon fatty acid content and decrease in n-3 LC-PUFA content in the muscle and liver of rainbow trout (Oncorhynchus mykiss), Japanese seabass (Lateolabrax japonicus) and large yellow croaker (Larimichthys crocea), suggesting that these fis ...[more]

PMID: 28067297

Similar Datasets

Project description:The rabbitfish Siganus canaliculatus was the first marine teleost demonstrated to have the ability for the biosynthesis of long-chain (≥C20) polyunsaturated fatty acids (LC-PUFA) from C18 PUFA precursors, and all the catalytic enzymes including two fatty acyl desaturase 2 (Δ4 Fads2 and Δ6/Δ5 Fads2) and two elongases (Elovl4 and Elovl5) have been identified, providing a good model for studying the regulatory mechanisms of LC-PUFA biosynthesis in fish. Stimulatory protein 1 (Sp1) has been speculated to be a vital transcription factor in determining the promoter activity of Fads-like genes in fish, however its regulatory effects on gene expression and LC-PUFA biosynthesis have not been demonstrated. Bioinformatic analysis predicted potential Sp1 binding sites in the promoters of the rabbitfish Δ6/Δ5 fads2 and elovl5, but not in Δ4 fads2 promoter. Here we cloned full-length cDNA of the rabbitfish sp1 gene, which encoded a putative protein of 701 amino acids, and was expressed in all tissues studied with highest levels in gill and eyes. The dual luciferase reporter assay in HepG2 line cells demonstrated the importance of the Sp1 binding site for the promoter activities of both Δ6/Δ5 fads2 and elovl5. Moreover, the electrophoretic mobility shift assay confirmed the direct interaction of Sp1 with the two promoters. Insertion of the Sp1 binding site of Δ6/Δ5 fads2 promoter into the corresponding region of the Δ4 fads2 promoter significantly increased activity of the latter. In the Siganus canaliculatus hepatocyte line (SCHL) cells, mRNA levels of Δ6/Δ5 fads2 and elovl5 were positively correlated with the expression of sp1 when sp1 was overexpressed or knocked-down by RNAi or antagonist (mithramycin) treatment. Moreover, overexpression of sp1 also led to a higher conversion of 18:2n-6 to 18:3n-6, 18:2n-6 to 20:2n-6, and 18:3n-3 to 20:3n-3, which related to the functions of Δ6/Δ5 Fads2 and Elovl5, respectively. These results indicated that Sp1 is involved in the transcriptional regulation of LC-PUFA biosynthesis by directly targeting Δ6/Δ5 fads2 and elovl5 in rabbitfish, which is the first report of Sp1 involvement in the regulation of LC-PUFA biosynthesis in vertebrates.

Dataset Information

Regulation of FADS2 transcription by SREBP-1 and PPAR-? influences LC-PUFA biosynthesis in fish.

Publications

Regulation of FADS2 transcription by SREBP-1 and PPAR-α influences LC-PUFA biosynthesis in fish.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets