CFTR/Regulation of CL Secretion in Normal and CF Airways

描述（由申请人提供）：在过去的15年里，该基金的长期目标是了解CFTR的Cl-通道和调节功能。在上一个预算期间，我们特别关注PDZ结合结构域的作用，并询问CFTR是否是大分子复合物的成员。我们发现了一种新的蛋白质CAL，它将CFTR束缚在高尔基体内，并靶向CFTR在溶酶体中降解。我们还研究了NHE-RF和CAP 70这些含PDZ结构域的蛋白质如何与CAL相关，从而解决了为什么多个含PDZ结构域的蛋白质与CFTR结合的问题。本提案假定CFTR与CAL的PDZ结构域的相互作用的作用是通过将CFTR束缚在高尔基体并靶向CFTR进行降解或允许其加工到质膜来调节CFTR在血浆中的量。该提案进一步假设，CAL介导的决定是否CFTR注定要移动到质膜或不确定的两个相关的蛋白质，结合CAL，TC 10和syntaxin 6。该研究进一步表明，CAL-CFTR与这两种相关蛋白的相互作用在CFTR如何响应导致呼吸道疾病和感染的细菌毒素方面具有重要作用。总体目标是解决以下三个问题：成熟CFTR向质膜的运输是否受TC 10调节？成熟CFTR向质膜的运输受Syntaxin 6调节吗？细菌毒素如何在CFTR运输到质膜中起作用？ 相关性：该提议代表了一个新的研究领域，其对我们理解涉及影响Rho-GTP酶的毒素的肺部疾病和肺中的假单胞菌感染都有影响，其中毒素ExoS可能改变CFTR向膜的运输。一旦确定了关键途径并确定了它们的作用，就有可能开发药物来治疗性地改变决定CFTR命运的转换机制。

DESCRIPTION (provided by applicant): The long-term goal of the grant over the past 15 years has been to understand both the Cl- channel and regulatory functions of CFTR. In the previous budget period, we focused specifically on the role of the PDZ binding domain and asked whether CFTR is a member of a macromolecular complex. We discovered a new protein, CAL that tethers CFTR within the Golgi and targets CFTR for degradation in the lysosome. We also studied NHE-RF and CAP70 how these PDZ domain-containing proteins function in relation to CAL, thus addressing the issue of why multiple PDZ domain-containing proteins bind to CFTR. The present proposal posits that the role of the interaction of CFTR with the PDZ domain of CAL is to regulate the amount of CFTR at the plasma either by tethering it at the Golgi, and targeting CFTR for degradation or allowing it to process to the plasma membrane. The proposal hypothesizes further, that the CAL-mediated decision whether CFTR is destined to move to the plasma membrane or not is determined by two associated proteins that bind to CAL, TC10 and syntaxin 6. The grant suggests further that the CAL-CFTR interaction with these two associated proteins has an important role in how CFTR responds to bacterial toxins that lead to diarrheal diseases and infection in the airways. The overall goal is to address the following three questions: Is the trafficking of mature CFTR to the plasma membrane regulated by TC10? Is the trafficking of mature CFTR to the plasma membrane regulated by Syntaxin6? How do bacterial toxins function in the trafficking of CFTR to the plasma membrane? Relevance: The proposal represents a new area of investigation with implications both for our understanding of diarrheal diseases involving toxins that affect Rho-GTPases and for Pseudomonas infection in lung where the toxin ExoS, may alter CFTR trafficking to the membrane. Once the critical pathways are identified and their roles established, it may be possible to develop drugs to therapeutically alter the switching mechanisms that determine CFTR's fate.