甘油-3-磷酸酰基转移酶在植物脂质代谢、生长及逆境反应中的作用

Glycerol-3-phosphate acyltransferase in lipid metabolism,growth and response to stresses in plants

甘油脂质是高等植物中含量最丰富的脂质,其种类包括磷脂、糖脂、油脂及胞外脂质等,广泛参与不同的生物过程。甘油-3-磷酸酰基转移酶(GPAT)利用各种脂肪族酰基或其衍生物作为底物催化甘油-3-磷酸(G3P)脂酰基化反应形成溶血磷脂酸(LPA),是脂质合成代谢途径中的限速酶。植物GPAT家族含有多个成员,根据其亚细胞定位、酶活性及底物选择性,拟南芥GPAT家族10个成员可分为3类。不同的GPAT具有独特的分子结构、活性调控及时空分布,并参与膜磷脂、甘油三脂、角质及软木脂合成代谢过程。研究表明极具分子异质性的GPAT在植物生长、发育和逆境胁迫反应过程中发挥着重要作用。

Plant glycerolipids are the most abundant lipids including phospholipids, galactolipids, storage lipids, and extralipids, and are involved in various biological processes. Glycerol-3-phosphate acyltransferase（GPAT） catalyzes the acylation of glycerol-3-phosphate（G3 P） to produce lysophosphatidic acid using fatty acids or oxidized fatty acids as substrates, which is a committed step reaction in glycerolipid biosynthesis pathway. GPAT family in plants is composed of multiple members and 10 GPATs in Arabidopsis thaliana are divided into three groups based on subcellular localization, enzymatic activity and substrate selectivity. Each member of plant GPATs exhibits distinguishable properties in molecular structure, activity, and temporal-spatial distribution. The GPAT activation is involved in the synthesis of various lipids such as membrane phospholipids, triacylglycerol, cutins, and suberins. Increasing evidence showed that the molecular heterogeneity of GPATs plays important roles in plant growth, development and response to stresses.