Cloning, Tissue Expression Analysis, and Functional Characterization of Two Δ6-Desaturase Variants of Sea Bass (Dicentrarchus labrax L.)

Autor: Heiner Kuhl, F. Geay, Hervé Le Delliou, Richard Reinhardt, Ester Santigosa, Chantal Cahu, Thierry Tonon, Jose L. Zambonino-Infante, Laurent Corcos, David Mazurais
Přispěvatelé: Nutrition, Métabolisme, Aquaculture (NUMEA), Institut National de la Recherche Agronomique (INRA), Unité mixte de recherche nutrition aquaculture et génomique (NUAGE), Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université Pierre et Marie Curie - Paris 6 (UPMC), Signaux oligosaccharidiques et lipidiques (SOL), Station biologique de Roscoff [Roscoff] (SBR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-GOEMAR-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Molecular Genetics (MPIMG), Max-Planck-Gesellschaft, Université de Bretagne Occidentale, Faculté de Médecine, Université européenne de Bretagne - European University of Brittany (UEB), Université Sciences et Technologies - Bordeaux 1-Institut National de la Recherche Agronomique (INRA)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
Rok vydání: 2010
Předmět:
Zdroj: Marine Biotechnology (1436-2228) (Springer), 2011-02, Vol. 13, N. 1, P. 22-31
Marine Biotechnology
Marine Biotechnology, 2011, 13 (1), pp.22-31. ⟨10.1007/s10126-010-9264-4⟩
Marine Biotechnology, Springer Verlag, 2011, 13 (1), pp.22-31. ⟨10.1007/s10126-010-9264-4⟩
ISSN: 1436-2236
1436-2228
DOI: 10.1007/s10126-010-9264-4
Popis: Fish are the main source of the n-3 highly unsaturated fatty acids, which are crucial for human health. Their synthesis from C(18) precursors is mediated by desaturases and elongases, but the activity of these enzymes has not been conclusively established in marine fish species. This study reports the cloning, tissue expression, and functional characterization of a sea bass (Dicentrarchus labrax L.) Δ6-desaturase and one of its splicing variants. Two cDNAs with open reading frames of 1,346 and 1,354 bp were cloned and named D6D and D6D-V, respectively. Both deduced protein sequences (445 and 387 amino acids, respectively) contained two transmembrane regions and the N-terminal cytochrome b(5) domain with the HPGG motif characteristic of microsomal desaturases. D6D presents three histidine-rich regions, whereas in D6D-V, an insertion of eight nucleotides in the boundaries of exons 10 and 11 modified the third histidine-rich domain and led to insertion of a premature STOP codon, resulting in a shorter predicted protein. Quantitative real-time polymerase chain reaction assay of gene expression showed that D6D was highly expressed in the brain and intestine, and to a lesser extent, in muscle and liver; meanwhile, D6D-V was expressed in all tissues tested, but at level at least 200-fold lower than D6D. Functional analysis in yeast showed that sea bass D6D encodes a fully functional Δ6-desaturase with no residual Δ5-desaturase activity. This desaturase does not exhibit a clear preference for n-3 versus n-6 C(18) substrates. Interestingly, D6D-V is a nonfunctional protein, suggesting that the C-terminal end is indispensable for protein activity.
Databáze: OpenAIRE
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