Shaanxi Key Laboratory of Molecular Biology for Agriculture, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
Food Funct. 2022 May 23;13(10):5870-5882. doi: 10.1039/d2fo00246a.
Delta-5 desaturase (D5D), encoded by the fatty acid desaturase 1 (FADS1) gene, is a rate-limiting enzyme in polyunsaturated fatty acid (PUFA) synthesis that influences the PUFA levels in milk fat. However, the function and molecular mechanism of FADS1 in milk fat metabolism remain largely unknown. The overexpression increased the triglyceride content, lipid droplet size, and expression of genes related to fatty acid synthesis ( and ), intracellular fatty acid transporters ( and ) and triacylglycerol synthesis gene (). It also significantly promoted the SREBP1 nuclear translocation by inhibiting the AMPK activation. In addition, FADS1 overexpression inhibited cell proliferation and arrested cell cycle at the G1 phase. These findings reveal a novel FADS1-AMPK-SREBP1 pathway regulating milk fat production in the goat mammary gland.
德尔塔-5 去饱和酶（D5D），由脂肪酸去饱和酶 1（FADS1）基因编码，是多不饱和脂肪酸（PUFA）合成中的限速酶，影响牛奶脂肪中的 PUFA 水平。然而，FADS1 在乳脂代谢中的功能和分子机制在很大程度上仍然未知。过表达增加了甘油三酯含量、脂滴大小以及与脂肪酸合成（FASN 和 ACC）、细胞内脂肪酸转运蛋白（CD36 和 FATP4）和三酰基甘油合成基因（DGAT1）相关的基因的表达。它还通过抑制 AMPK 激活显著促进 SREBP1 核易位。此外，FADS1 过表达抑制细胞增殖并将细胞周期阻滞在 G1 期。这些发现揭示了一条新的 FADS1-AMPK-SREBP1 通路，调节山羊乳腺中的乳脂生成。
