Fatty Acid Synthase from Arabidopsis thaliana and Related Plants

9405588 Jaworski植物中的脂肪酸生物合成是提供在膜脂质和植物油中发现的脂肪酰基组分所必需的主要代谢途径。在我们的实验室中，3-酮脂酰-酰基载体蛋白（ACP）合酶III（KAS III）活性的发现导致了关于脂肪酸形成调控的新问题。我们已经表明，KAS III是脂肪酸合成开始时的主要机制，但它是必需的步骤吗？为了回答这个问题，我们将：（1）分析拟南芥和其他植物中KAS III活性改变的影响。KAS III的表达将增加和减少在拟南芥中的反义和正义构建体的cDNA;（2）试图确定其他KAS和分析他们的角色中链脂肪酸的合成;和（3）我们将确定KAS III是否能够在体内条件下与脂肪酸合成酶功能的其他酶相互作用，使用“双杂交”系统检测蛋白质-蛋白质相互作用。植物中的脂肪酸生物合成是提供在膜脂质和植物油中发现的脂肪酰基组分所必需的主要代谢途径。正在研究的领域旨在回答有关调节和个人反应对这一重要途径的贡献的基本问题。此外，将启动一项研究，探讨有关这一途径的分子组织的问题。植物中脂肪酸生物合成的基本反应是什么？它们是如何被控制的？该实验室已经证明，由酶3-酮脂酰基-酰基载体蛋白合酶或KAS III引起的反应是开始脂肪酸合成过程的主要途径。但这是否是一个必要的反应还没有得到证明。找到答案的一种方法是研究KAS III在脂肪酸形成过程中如何在细胞内运作。看来，许多参与脂肪酸形成的酶聚集在一起，形成大的、可操作的复合物。因此，据信，如果KAS III或其他KAS型酶也在相同的脂肪酸产生酶聚集体中结合，则这些酶在脂肪酸形成中的重要作用将变得更加清楚。***

9405588 Jaworski Fatty acid biosynthesis in plants is a primary metabolic pathway that is necessary to provide the fatty acyl components found in the lipids of membranes and in vegetable oils. In our laboratory, the discovery of 3-ketoacyl-acyl carrier protein (ACP) synthase III (KAS III) activity has led to new questions about regulation of fatty acid formation. We have shown that KAS III is the predominant mechanism at the start of fatty acid synthesis, but is it a required step? To answer this question, we will: (1) analyze the effect of altered KAS III activity in Arabidopsis thaliana and other plants. KAS III expression will be both increased and decreased in Arabidopsis with antisence and sense constructs of its cDNA; (2) attempt to identify other KASs and analyze their roles in synthesis of medium chain fatty acids; and (3) we will determine if KAS III is capable of interacting with other enzymes of fatty acid synthase function under in vivo conditions, using a 'two-hybrid' system to detect protein-protein interaction. %%% Fatty acid biosynthesis in plants is a primary metabolic pathway that is necessary to provide the fatty acyl components found in the lipids of membranes and in vegetable oils. Areas under study are intended to answer basic questions concerning the regulation and contribution of individual reactions to this essential pathway. In addition, a study will be initiated to probe questions concerning the molecular organization of this pathway. What are the basic reactions of fatty acid biosynthesis in plants and how are they controlled? It has been demonstrated by this laboratory that a reaction caused by the enzyme 3-ketoacyl-acyl carrier protein synthase, or KAS III, is the predominant route for beginning the process of fatty acid synthesis. But whether this in a required reaction has not been proved. One approach to find an answer is to study how KAS III operates inside the cell during fatty acid formation. It appears that many of t he enzymes that are involved in fatty acid formation group together and form large, operational complexes. As a result, it is believed that the essential role for KAS III, or other KAS-type enzymes, in fatty acid formation will become clearer if these enzymes also associate themselves in the same fatty acid producing enzyme aggregations. ***