Outward Trafficking of CFTR

该基金的长期目标是了解CFTR的加工和运输到质膜是如何调节的。CFTR是一种在几种上皮细胞如气道中在顶端细胞膜起作用的蛋白质。我们以前已经表明，CFTR从高尔基体到质膜的运输受到三种蛋白质的调节，即含PDZ结构域的蛋白质CAL、小分子量GTdR、TC 10和SNARE蛋白质STX 6，我们现在将其称为CAL复合物。本提案假定，除了其在调节CFTR的表面表达中的作用之外，CAL还通过与细胞质量控制机制中的蛋白质相互作用在调节未成熟CFTR蛋白质的量中起作用，所述细胞质量控制机制包括新合成蛋白质的ER加工，随后是蛋白酶体和攻击体降解不正确折叠的蛋白质。这一过程被称为ERAD。为了进一步研究这一点，我们建议解决以下问题：1。CAL复合物在处理未成熟wt-和A508-CFTR中的生理作用是什么？确切地说，不成熟的CFTR的加工是如何通过ER被TC 10-GTP/GDP循环和STA 2调节的？2. CAL复合物在调节细胞表面的A508-CFTR中的生理作用是什么？确切地说，被拯救的A508-CFTR向质膜的运输是如何被TCI 0-GTP/GDP循环调节的？3. CAL复合物是否与ER质量控制机制中的关键蛋白质相互作用？所有这些研究都将采用各种方法的组合，以加强整体计划项目赠款。同样，该提案将获得PPG成员的专业知识和合作，这将提高成功的可能性，超越作为单独的独立应用程序所能实现的可能性。最终的目标是提供新的见解的生理过程中CFTR如何在极化上皮组织中的大分子复合物的功能。

The long-term goal ofthe grant is to understand how the processing and trafficking of CFTR to the plasma membrane Is regulated. CFTR Is a protein that in several epithelia such as the airway functions at the apical cell membrane. We have shown previously that the trafficking of CFTR from the Golgi to the plasma membrane is regulated by three proteins, the PDZ domain containing protein, CAL, the small molecular weight GTPase, TC10, and the SNARE protein, STX6, which we now refer to as the CALcomplex. The present proposal posits that In addition to its role in regulating the surface expression of CFTR, CAL also plays a role In regulating the amount of immature CFTR protein by interacting with proteins in the cell's quality control mechanism which includes ER processing of newly synthesized proteins followed by proteasomal and aggresomal degradation of incorrectly folded proteins. A process termed ERAD. To study this further we propose to address the following: 1. What is the physiological role ofthe CAL-complex in the processing the Immature wt- and A508-CFTR? Precisely how is the processing of immature CFTR by the ER regulated by the TC10-GTP/GDP cycle and bySTXe? 2. What is the physiological role ofthe CAL-complex in the regulation of rescued A508-CFTR at the cell surface? And precisely how is the trafficking of rescued A508-CFTR to the plasma membrane regulated by TCI 0-GTP/GDP cycle? 3. Does the CAL complex interact with key proteins in the ER quality control mechanism? All of these studies will employ a combination of approaches that will strength the overall Program Project Grant. Likewise, the proposal will gain expertise and collaboration from members of the PPG that will enhance the likelihood of success beyond what could be achieved as an individual stand alone application. The ultimate goal is to provide novel insights into physiological process regarding how CFTR functions in a macromolecular complex In polarized epithelial tissues.