GABA TRANSPORTER INTERACTING DOMAINS

描述：(申请人摘要) 大脑中的神经递质水平对正常的大脑功能至关重要。 神经递质水平异常，导致不适当的神经 信号，是一系列不同的大脑疾病的基础。比如癫痫， 兴奋性毒性细胞死亡、抑郁和一些与药物有关的情况 滥用都与大脑中递质水平的异常有关。神经递质 转运蛋白是一种蛋白质，位于神经元和神经胶质细胞上，具有部分功能 将细胞外环境中的递质输送到细胞内。因此， 它们在调节突触信号方面起着核心作用。虽然很多事情都是 了解各种神经递质的渗透特性 转运体(例如，转运率、底物亲和力、导电态)， 关于转运蛋白的特定结构域如何 参与渗透过程。此外，虽然众所周知， 转运蛋白的功能是否可以调节，调节的程度 通过对渗透中涉及的域的操纵而发生的情况尚不清楚。 这个应用程序的主要目标是定义分子内和 GABA转运体GAT1调控中的分子间相互作用。 具体目标1是检验氨基末端细胞质的假设 GABA转运体GAT1的尾部通过 与转运蛋白内部胞质环的相互作用。具体目标2 是为了验证这样一种假设，即与氨基相互作用的蛋白质 GAT1的末端尾巴通过阻止GAT1的 N-末端尾巴与胞质内环相互作用 传送器。具体目标3是检验分子间相互作用假设 负向调节转运蛋白功能的相互作用可以通过 生理上相关的因素。 这些研究很重要，因为它们将(I)确定新的监管角色 在细胞内转运体结构域的渗透中；(Ii)阐明一种新的 转运蛋白功能的细胞调控机制 蛋白质之间的相互作用；以及(Iii)提供可能有助于 旨在调节转运蛋白功能的治疗策略 与递质水平异常有关的紊乱。

DESCRIPTION: (Applicant's Abstract) Neurotransmitter levels in brain are critical for normal brain function. Abnormal levels of neurotransmitter, resulting in inappropriate neural signaling, underlie a diverse list of brain disorders. For example, epilepsy, excitotoxic cell death, depression, and a number of conditions related to drug abuse are all related to abnormal transmitter levels in brain. Neurotransmitter transporters are proteins, located on neurons and glia, that function in part to transport transmitter from the extracellular milieu into cells. As such, they play a central role in regulating synaptic signaling. While much is being learned about the permeation properties of various neurotransmitter transporters (e.g., transport rates, substrate affinities, conducting states), little is known about how particular structural domains of the transporter participate in the permeation process. Furthermore, while it is known that transporter function can be regulated, the extent to which the regulation occurs through manipulation of the domains involved in permeation is not known. The major goal of this application is to define the role of intra-molecular and inter-molecular interactions in regulation of the GABA transporter GAT1. Specific Aim 1 is to test the hypothesis that the amino terminal cytoplasmic tail of the GABA transporter GAT1 positively regulates GABA transport through interactions with internal cytoplasmic loops of the transporter. Specific Aim 2 is to test the hypothesis that proteins that physically interact with the amino terminal tail of GAT1 negatively regulate GAT1 function by preventing the N-terminal tail from interacting with the internal cytoplasmic loops of the transporter. Specific Aim 3 is to test the hypothesis that intermolecular interactions that negatively regulate transporter function can be modulated by physiologically relevant factors. These studies are important because they will (i) define a new regulatory role in permeation for intracellular transporter domains; (ii) elucidate a novel mechanism for the cellular regulation of transporter function through protein-protein interactions; and (iii) provide data that could be useful in strategies aimed at regulating transporter function in the treatment of disorders related to abnormal transmitter levels.