POSTTRANSLATIONAL PROTEIN TRANSPORT INTO YEAST ER

本申请旨在了解 翻译后跨膜转运 酿酒酵母的网囊。具体目标1涉及机制 靶向底物的能力。胞质分子伴侣的存在及其重要性 或靶向分子进行评估。第二个具体目标将决定 信号序列在移位信道的选通上的作用。它 将测试信号序列取代了 因此，打开了易位通道。具体目标3 是确定易位子组分的化学计量。 包含易位通道的3或4个Sec61p复合物的估计 是基于电子显微技术制作的，这将是 生化测试将测试Sec62p在催化组装中的作用。 最后，具体目标4试图了解管腔Hsp70在细胞凋亡中的作用。 易位过程它将检验这种蛋白质作为一种 分子棘轮，而不是一个机器，“拉”的蛋白质通过 膜的

The application seeks to understand the mechanism of posttranslational translocation across the membrane of the endoplasmic reticulum of Saccharomyces cerevisiae. Specific Aim 1 addresses the mechanism of targeting of substrates. The presence and importance of cytosolic chaperones or targeting molecules will be assessed. The second Specific Aim will determine the role of the signal sequence on the gating of the translocating channel. It will test the hypothesis that the signal sequence displaces a component of the translocon, and as a result, opens the translocation channel.. Specific Aim 3 is to determine the stoicheometry of the components of the translocon. Estimations of 3 or 4 Sec61p complexes comprising the translocation channel have been made based on electron micrographic techniques, and this will be tested biochemically. A role of Sec62p in catalyzing assembly will be tested. Finally, Specific Aim 4 seeks to understand the role of luminal Hsp70 in the translocation process. It will test the hypothesis that this protein works as a molecular ratchet rather than a machine that "pulls" the protein through the membrane.