Transcription factor pparαb activates fads2s to promote LC-PUFA biosynthesis in the golden pompano Trachinotus ovatus (Linnaeus 1758)
Autor: | Shigui Jiang, Liang Guo, Dianchang Zhang, Huayang Guo, Ke-Cheng Zhu, Nan Zhang, Bao-Suo Liu |
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Rok vydání: | 2020 |
Předmět: |
Fatty Acid Desaturases
Fish Proteins Transcription Genetic FADS2 02 engineering and technology Biochemistry 03 medical and health sciences Fish Oils Structural Biology Transcription (biology) Animals PPAR alpha Binding site Promoter Regions Genetic Molecular Biology Transcription factor Trachinotus ovatus 030304 developmental biology chemistry.chemical_classification 0303 health sciences Binding Sites biology Fishes Brain Promoter General Medicine Peroxisome 021001 nanoscience & nanotechnology biology.organism_classification Liver chemistry Fatty Acids Unsaturated 0210 nano-technology Transcription Factors Polyunsaturated fatty acid |
Zdroj: | International Journal of Biological Macromolecules. 161:605-616 |
ISSN: | 0141-8130 |
Popis: | Fatty acyl desaturase 2 (fads2) is a rate-limiting enzyme in long chain polyunsaturated fatty acids (LC-PUFAs) biosynthesis. In mammals, the lipid metabolism is modulated by a transcription factor, peroxisome proliferator-activated receptor alpha β (pparαβ); however, the detailed mechanism via pparαβ regulates fads2 remains unclear in fish. In the present study, we identified the sequence features of Trachinotus ovatus fatty acyl desaturase 2a (Tofads2a) and fatty acyl desaturase 2b (Tofads2b), which both encoded 442 amino acid polypeptides containing cytochrome-b5-like domains and three representative histidine-rich domains. The Phylogenetic and genome organization analyses revealed characteristic phylogeny: the majority of fads2s exhibited a highly conserved exon/intron architecture. Tissue expression patterns by quantitative real-time PCR (qRT-PCR) showed that the two Tofads2s were prominently expressed in the brain. A nutritional study indicated that the transcription of the two Tofads2s was significantly implicated by treatment with a 1: 1 ratio of fish oil: soybean oil (FO:SO) in the liver and brain. Furthermore, functional characterization in yeast demonstrated that both Tofads2a and Tofads2b possessed Δ4/Δ5/Δ8 desaturation activity. Furthermore, promoter activity assays showed that the expressions of the two Tofads2s were actively regulated by pparαβ. Moreover, mutation analyses showed that the M1 and M4/M5 binding sites of pparαβ were functionally vital for binding to Tofads2a and Tofads2b promoters, respectively. Transcriptional activities of the two Tofads2s promoters were significantly reduced after targeted mutation of M1 or M4/M5. Electrophoretic mobile shift assays (EMSAs) verified that pparαβ interacted with the M1 binding site in Tofads2a promoter to accommodate Tofads2a transcription. Briefly, pparαβ plays an important role in Tofads2 expression and may promote the LC-PUFAs biosynthesis by regulating the expression of two Tofads2s. |
Databáze: | OpenAIRE |
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