TOC COMPLEX IN PROTEIN TARGETING TO CHLOROPLASTS

这项建议中的实验结合了体内研究 Schnell博士将在那里研究突变体对 叶绿体生物发生的TOC复合体，生化研究旨在 阐明TOC复合体中各亚基的功能作用 膜转位。在这笔赠款中提出了5个具体目标 申请。第一个目标是研究Toc34，75和 159在拟南芥菜中的表达及其突变形式的后果 蛋白质。这项工作是与凯斯勒博士持续合作的一部分 苏黎世，一位A.thaliana遗传学专家。第二个目标与 第一个，因为它将使用类似的方法来探索 他们发现的两个基因TOC 132和ToC 120似乎是成员 属于同一蛋白质家族。第三个目标集中在功能 对TOC 159的剖析。具体地说，建议研究这一角色 GTP酶在识别从胞浆输入的前蛋白中的作用 叶绿体。有人建议寻找其他促进蛋白质 通过使用蛋白质-蛋白质相互作用的既定方法进行这种识别。 其他蛋白质也是TOC复合体的一部分，AIMS 4和5将在体外使用 研究它们在蛋白质进口中的潜在调节作用以及它们的 联系人地图。

The experiments in this proposal combine in vivo studies in Arabidopsis thaliana, where Dr. Schnell will study the influence of mutants of the TOC complex of chloroplast biogenesis, with biochemical studies aimed to elucidate the functional role of various subunits of the TOC complex in membrane translocation. There are 5 specific aims proposed in this grant application. The first aim involves the study of null mutants of Toc34,75 and 159 in A. thaliana and consequences of expressing mutated forms of these proteins. This work is part of an ongoing collaboration with Dr. Kessler at ETH, Zurich, an expert in A. thaliana genetics. The second aim is related to the first one, in that it will use similar methods to explore the function of Toc 132 and Toc 120, two genes they have discovered that appear to be members of the same family of proteins. The third aim focuses on the functional dissection of Toc 159. Specifically it is proposed to study the role of this GTPase in the recognition of pre-proteins that are imported from the cytosol to the chloroplast. It is proposed to search for other proteins that facilitate this recognition by using established methods of protein-protein interaction. Other proteins are part of the TOC complex, and aims 4 and 5 will use in vitro assays to study their potential regulatory role in protein import and their contact map.