Molecular and functional characterisation of a putative elovl4 gene and its expression in response to dietary fatty acid profile in Atlantic bluefin tuna (Thunnus thynnus)

Publication date: Available online 24 October 2019Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular BiologyAuthor(s): Mónica B. Betancor, Angela Oboh, Aurelio Ortega, Gabriel Mourente, Juan C. Navarro, Fernando de la Gándara, Douglas R. Tocher, Óscar MonroigAbstractElongation of very long-chain fatty acid 4 (Elovl4) proteins are involved in the biosynthesis of very long-chain (>C24) fatty acids and in many teleost fish species they are key enzymes in the pathway for the production of docosahexaenoic acid (DHA; 22:6n-3) from eicosapentaenoic acid (EPA; 20:5n-3). Therefore, Elovl4 may be particularly important in Atlantic bluefin tuna (ABT; Thunnus thynnus) characterised by having high DHA to EPA ratios. The present study cloned and characterised both the function and expression of an elovl4 cDNA from ABT. The Elovl4 had an open reading frame of 915 base pairs encoding a putative protein of 304 amino acids. Alignment and phylogenetic analyses indicated that the Elovl4 isoform identified in the present study was an Elovl4b. Functional characterisation demonstrated that the Elovl4b enzyme had elongase activity towards all the polyunsaturated fatty acid (PUFA) substrates assayed. The ABT Elovl4b contributed to DHA biosynthesis by elongation of EPA and DPA to 24:5n-3, the latter being desaturated to 24:6n-3 by the action of fads2 (Δ6 desaturase). Additionally, the ABT Elovl4b has a role in the biosynthesis of very long-chain PUFA up to C34, comp...
Source: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology - Category: Molecular Biology Source Type: research