The fatty acid desaturase 3 gene encodes for different FADS3 protein isoforms in mammalian tissues

Philippe Legrand,Hélène Blanchard,Frédérique Pédrono,Sabine D'Andréa,Stéphanie Daval,Maela Kloareg,Vincent Rioux

doi:10.1194/jlr.m000588

Philippe Legrand, Hélène Blanchard + Show 5 more

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https://doi.org/10.1194/jlr.m000588

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Abstract

In 2000, Marquardt et al. (A. Marquardt, H. Stöhr, K. White, and B. H. F. Weber. 2000. cDNA cloning, genomic structure, and chromosomal localization of three members of the human fatty acid desaturase family. Genomics. 66: 176-183.) described the genomic structure of the fatty acid desaturase (FADS) cluster in humans. This cluster includes the FADS1 and FADS2 genes encoding, respectively, for the Delta 5- and Delta 6-desaturases involved in polyunsaturated fatty acid biosynthesis. A third gene, named FADS3, has recently been identified but no functional role has yet been attributed to the putative FADS3 protein. In this study, we investigated the FADS3 occurrence in rat tissues by using two specific polyclonal antibodies directed against the N-terminal and C-terminal ends of rat FADS3. Our results showed three potential protein isoforms of FADS3 (75 kDa, 51 kDa, and 37 kDa) present in a tissue-dependent manner. The occurrence of these FADS3 isoforms did not depend on the mRNA level determined by real-time PCR. In parallel, mouse tissues were also tested and showed the same three FADS3 isoforms but with a different tissue distribution. Finally, we reported the existence of FADS3 in human cells and tissues but different new isoforms were identified. To conclude, we showed in this study that FADS3 does exist under multiple protein isoforms depending on the mammalian tissues. These results will help further investigations to determine the physiological function of FADS3.

Highlights

Introduction66: 176–183.) described the genomic structure of the fatty acid desaturase (FADS) cluster in humans
Fads2 mRNA and, to a lesser extent, Fads1 mRNA were highly abundant especially in testis whereas Fads3 mRNA was not represented. These data demonstrated that Fads3 transcripts, as well as Fads1 and Fads2 transcripts, were distributed in a tissue-specific and sex-dependent manner
This study presented the cloning of Fads3 and, for the first time, the occurrence of the natural FADS3 protein in mammalian tissues or cells, which demonstrated that Fads3 is not a pseudogene

Summary

Introduction

66: 176–183.) described the genomic structure of the fatty acid desaturase (FADS) cluster in humans. Our results showed three potential protein isoforms of FADS3 (75 kDa, 51 kDa, and 37 kDa) present in a tissue-dependent manner. We showed in this study that FADS3 does exist under multiple protein isoforms depending on the mammalian tissues. These results will help further investigations to determine the physiological function of FADS3.—Pédrono, F., H. The fatty acid desaturase 3 gene encodes for different FADS3 protein isoforms in mammalian tissues. Marquardt et al [6] described the human genomic structure of the fatty acid desaturase (FADS) cluster including the FADS1 and FADS2 genes coding, respectively, for the ⌬5- and ⌬6-desaturases.

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