The Endoplasmic Reticulum-Associated Maize GL8 Protein Is a Component of the Acyl-Coenzyme A Elongase Involved in the Production of Cuticular Waxes1
The Endoplasmic Reticulum-Associated Maize GL8 Protein Is a Component of the Acyl-Coenzyme A Elongase Involved in the Production of Cuticular Waxes1
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DOI：
10.1104/pp.010621
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发表时间：
2002-03
期刊：
影响因子：
7.4
通讯作者：
Xiaojie Xu;Charles R. Dietrich;R. Lessire;B. Nikolau;P. Schnable
中科院分区：
文献类型：
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作者：
Xiaojie Xu;Charles R. Dietrich;R. Lessire;B. Nikolau;P. Schnable
gl8基因是玉米（Zea mays）幼苗叶片上表皮蜡正常积累所必需的。预测的GL8蛋白表现出显着的序列相似性，一类酶，催化还原酮基团的羟基。利用大肠杆菌表达的GL8蛋白制备多克隆抗体，研究该蛋白在植物体内的功能。亚细胞分级实验表明，GL8蛋白与内质网膜。此外，针对部分纯化的韭菜（Allium porrum）微粒体酰基辅酶A（CoA）延伸酶的多克隆抗体可以与E.大肠杆菌表达的GL8蛋白。此外，抗GL8免疫球蛋白G抑制了韭菜和玉米微粒体酰基辅酶A延长酶对硬脂酰辅酶A的体外延长。总之，这些发现表明GL8蛋白是酰基辅酶A延长酶的组分。此外，抗GL8免疫球蛋白G不显著抑制3-酮脂酰-CoA合酶、3-酮脂酰-CoA脱氢酶和（E）2，韭菜或玉米酰基辅酶A延伸酶的3-烯酰辅酶A还原酶部分反应进一步支持了我们先前的假设，即GL8蛋白在非常长的-β-酮酰基辅酶A延伸过程中起β-酮酰基还原酶的作用。产生表皮蜡所需的链状脂肪酸。
The gl8 gene is required for the normal accumulation of cuticular waxes on maize (Zea mays) seedling leaves. The predicted GL8 protein exhibits significant sequence similarity to a class of enzymes that catalyze the reduction of a ketone group to a hydroxyl group. Polyclonal antibodies raised against the recombinantEscherichia coli-expressed GL8 protein were used to investigate the function of this protein in planta. Subcellular fractionation experiments indicate that the GL8 protein is associated with the endoplasmic reticulum membranes. Furthermore, polyclonal antibodies raised against the partially purified leek (Allium porrum) microsomal acyl-coenzyme A (CoA) elongase can react with the E. coli-expressed GL8 protein. In addition, anti-GL8 immunoglobulin G inhibited the in vitro elongation of stearoyl-CoA by leek and maize microsomal acyl-CoA elongase. In combination, these findings indicate that the GL8 protein is a component of the acyl-CoA elongase. In addition, the finding that anti-GL8 immunoglobulin G did not significantly inhibit the 3-ketoacyl-CoA synthase, 3-ketoacyl-CoA dehydrase, and (E) 2,3-enoyl-CoA reductase partial reactions of leek or maize acyl-CoA elongase lends further support to our previous hypothesis that the GL8 protein functions as a β-ketoacyl reductase during the elongation of very long-chain fatty acids required for the production of cuticular waxes.