Understanding GABAA receptor protein folding and misfolding

项目描述 蛋白质稳态，细胞蛋白质组的最佳状态，不断受到内在应激的挑战，例如 遗传性易错误折叠蛋白质、环境和衰老。离子通道蛋白稳态缺乏 导致各种离子通道疾病，称为通道病，这通常是由过量的 内质网相关降解（ERAD）和膜运输效率低下， 相应的离子通道蛋白含有错误折叠倾向突变。我们用伽马射线- 氨基丁酸A型（GABAA）受体，主要抑制性神经递质门控离子通道 在哺乳动物中枢神经系统，作为一个代表性的离子通道，阐明其折叠 和内质网（ER）中的ERAD途径。GABAA受体与 细胞中的蛋白质网络对于维持折叠、降解、运输和功能至关重要。 GABAA受体。然而，维持GABAA受体蛋白稳态的分子机制是 没有被很好地理解。特发性癫痫与GABAA功能丧失有很强的遗传联系 受体。我们专注于研究导致错误折叠，广泛降解， 并因此丧失突变型GABAA受体的功能。我们的长期目标是执行详细的 分子机制研究，以阐明GABAA受体的折叠，组装，降解 在细胞中受到调节，并使用获得的原则来纠正癫痫相关的错误折叠的GABAA 受体。在这里，在具体目标1中，我们的目标是阐明伴侣的协调参与， 折叠酶在引导ER中GABAA受体折叠中的作用。在具体目标2中，我们旨在 确定错误折叠倾向突变GABAA受体的ERAD途径。在具体目标3中，我们 建议重塑ER蛋白质稳态网络，以纠正致病性蛋白质的错误折叠和功能， GABAA受体。这项拟议的研究将提供有关恢复的原理证明案例 蛋白质稳态以改善由GABAA受体错误折叠引起的遗传性癫痫。

Project Description Proteostasis, an optimal state of the cellular proteome, is constantly challenged by intrinsic stress, such as inherited misfolding-prone proteins, environment, and aging. Proteostasis deficiency in ion channels leads to a variety of ion channel diseases called channelopathies, which are often caused by excessive endoplasmic reticulum-associated degradation (ERAD) and inefficient membrane trafficking of corresponding ion channel proteins harboring misfolding-prone mutations. We use gamma- aminobutyric acid type A (GABAA) receptors, the primary inhibitory neurotransmitter-gated ion channels in the mammalian central nervous systems, as a representative ion channel, to elucidate their folding and ERAD pathway in the endoplasmic reticulum (ER). The interaction between GABAA receptors and a network of proteins in cells is critical to maintain the folding, degradation, trafficking, and thus function of GABAA receptors. However, the molecular mechanism of maintaining GABAA receptor proteostasis is not well understood. Idiopathic epilepsy has a strong genetic linkage to loss of function of GABAA receptors. We focus on studying missense mutations that lead to misfolding, extensive degradation, and thus loss of function of mutant GABAA receptors. Our long term goal is to perform a detailed molecular mechanism study to elucidate how the folding, assembly, degradation of GABAA receptors are regulated in cells and use the principles acquired to correct epilepsy-associated misfolded GABAA receptors. Here, in Specific Aim 1, we aim to elucidate a coordinated engagement of chaperones and folding enzymes in directing the folding of GABAA receptors in the ER. In Specific Aim 2, we aim to determine the ERAD pathway of misfolding-prone mutant GABAA receptors. In Specific Aim 3, we propose to remodel the ER proteostasis network to correct the misfolding and function of pathogenic GABAA receptors. This proposed research will provide proof-of-principle cases about restoring proteostasis to ameliorate genetic epilepsy resulting from GABAA receptor misfolding.