水生动物脂肪酸去饱和酶基因相关进展

Progress on the Gene of Fatty Acid Desaturase in Aquatic Animals

长链多不饱和脂肪酸(long chain polyunsaturated fatty acids, LCPUFAs)对人体的生理功能有重要作用,但是人体合成LCPUFAs能力非常有限,水生动物因其口味鲜美以及富含LCPUFAs成为人类LCPUFAs的主要来源。水生动物体内多不饱和脂肪酸(polyunsaturated fatty acids, PUFAs)在脂肪酸去饱和酶(fatty aciddesaturase, Fad)和延长酶(Elongase)的催化下经过一系列脱氢和延长,可进一步转化成LCPUFAs。Fad 是合成PUFAs途径中的关键酶,它控制着PUFAs的不饱和程度。本研究在解释了PUFAs的相关理论的基础上,又进一步阐明了多数生物体内的LCPUFAs是如何以PUFAs为底物经过一系列脱氢和延长作用逐步合成的。研究发现了在LCPUFAs的生物合成过程中,Fad 起到了非常重要的作用。因此本研究解释了Fad 的相关理论基础,综述了Δ6、Δ5、Δ4、Δ8 和Δ9 这5 种Fad 的研究进展,同时了解了Fad 的转录因子和启动子的相互作用及营养对其表达调控已经是最新研究趋势,硬骨鱼中Δ6/5Fad 启动子的首次发现更是为我们研究LC-PUFA的合成机制的初步阶段提供了参考。

Longchain polyunsaturated fatty acids (LCPUFAs) play an important role in physiological function of human body, but the ability of human body to synthesize LCPUFAs is very limited, aquatic animals have become the main source of human LCPUFAs because of their delicious taste and abundant LCPUFAs. The polyunsaturated fatty acids (PUFAs) in aquatic animals can be further transformed into LCPUFAs by a series of dehydrogenation and prolongation under the catalysis of fatty acid desaturase (Fad) and elongase. Fad, a key enzyme in the synthesis of PUFAs, controls the unsaturated degree of PUFAs. On the basis of the explanation of the related theory of PUFAs, this study further clarified how LCPUFAs were synthesized by a series of dehydrogenation and prolongation with PUFAs as a substrate in most organisms. It was found that Fad played a very important role in the biosynthesis of LCPUFAs. Therefore, the theoretical basis of Fad was explained. The research progress of the five kinds of Fad, delta 6, delta 5, delta 4, delta 8 and delta 9, had been reviewed. At the same time, it was known that the interaction between the transcription factor and promoter of Fad and the regulation of nutrition on its expression were the latest research trends. The first discovery of delta 6/5 Fad promoter in the hard bone fish provided a reference for the preliminary stage of our study of the synthesis mechanism of LCPUFAs.