Understanding GABAA receptor protein folding and misfolding

项目说明 蛋白质平衡是细胞蛋白质组的一种最佳状态，不断受到内在压力的挑战，如 作为遗传的易错折叠蛋白质、环境和衰老。离子通道中的蛋白平衡缺陷 导致各种称为通道病的离子通道疾病，通常是由过量的 内质网相关降解(ERAD)与低效膜转运 相应的离子通道蛋白含有易错折叠的突变。我们用伽马- 氨基丁酸A型受体--主要的抑制性神经递质门控离子通道 在哺乳动物中枢神经系统中，作为代表性的离子通道，来阐明它们的折叠 内质网(ER)ERAD途径。GABAA受体与GABAA受体的相互作用 细胞中的蛋白质网络对维持折叠、降解、运输和功能至关重要 GABAA受体。然而，维持GABAA受体蛋白稳定的分子机制是 不是很清楚。特发性癫痫与GABAA功能丧失有很强的遗传关联 感受器。我们专注于研究导致错误折叠、广泛降解的错义突变， 从而丧失突变的GABAA受体的功能。我们的长期目标是执行一项详细的 GABAA受体折叠、组装、降解的分子机制研究 在细胞中被调节，并使用获得的原理来纠正癫痫相关的错误折叠的GABAA 感受器。在这里，在具体的目标1中，我们的目标是阐明伴侣和 折叠酶在引导内质网GABAA受体折叠中的作用。在具体目标2中，我们的目标是 确定易错折叠的突变型GABAA受体的ERAD途径。在具体目标3中，我们 建议重塑内质网蛋白平衡网络以纠正致病基因的错误折叠和功能 GABAA受体。这项拟议的研究将提供关于修复的原则证明案例 蛋白抑制剂用于改善由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.