GLUTAMATE TRANSPORT AND TRANSPORTERS FOREBRIAN NEURONS

描述：本研究的长期目标是更好地了解 谷氨酸转运在兴奋性脑损伤生理和病理生理中的作用 突触虽然谷氨酸转运被认为主要是一种 星形胶质细胞的功能，来自各种方法的证据表明， 神经元谷氨酸摄取机制也很重要， 兴奋性传递的生理学以及 兴奋性毒性我们研究了大鼠前脑神经元的谷氨酸转运， 培养，并发现谷氨酸转运的药理学是不同的， 从神经元转运蛋白EAAC 1的，并类似于GLT 1，已知 作为星形胶质细胞转运蛋白。我们克隆了谷氨酸转运蛋白的cDNA 图书馆由这些文化组成。我们发现，除了EAAC 1和GLT 1之外，还有一个 GLT 1的变体形式，其在C-末端11个氨基酸处不同于GLT 1的变体形式。 最初克隆的GLT 1。我们现在称原始形式为“GLT 1a”， 从神经元文库“GLT 1b”克隆的变体形式。“初步LM和EM 免疫细胞化学研究表明，GLT 1b定位于神经元， 以及前脑的星形胶质细胞。此外，GLT 1b，而不是GLT 1a，具有 PDZ-结构域相互作用共有序列在其C-末端。的假设 激发这个项目的是，GLT 1b是一个重要的神经元转运蛋白， 这种变异形式通过它的C末端与其他 这些蛋白质在功能上很重要，但GLT 1a无法获得。的 该项目的具体目标是： 1.比较GLT 1a和B在神经元培养物和脑中的表达。 假设是GLT 1b表达解释了 大脑神经元中GLT 1的mRNA。 2.用GLT 1b表征酵母双杂交筛选中发现的相互作用物。的 假设GLT 1b与一个或多个含有PDZ结构域相互作用， proteins. 3.表征蛋白质相互作用物对GLT 1a & B功能的影响。 假设GLT 1的变体形式的功能将受到影响 通过与其他蛋白质的相互作用。

DESCRIPTION: The long-term goal of this research is to better understand the role of glutamate transport in the physiology and pathophysiology of excitatory synapses. Although glutamate transport has been assumed to be largely a function of astrocytes, evidence from a variety of approaches suggests that neuronal glutamate uptake mechanisms are important as well, both for the physiology of excitatory transmission as well as for the pathophysiology of excitotoxicity. We studied glutamate transport in rat forebrain neurons in culture, and found that the pharmacology of glutamate transport was distinct from that of the neuronal transporter EAAC1, and resembled that of GLT1, known as an astrocyte transporter. We cloned glutamate transporters form a cDNA library made from these cultures. We found, in addition to EAAC1 and GLT1, a variant form of GLT1 that differs at the C-terminal 11 amino acids from the originally cloned GLT1. We now call the originally form "GLT1a," and the variant form cloned from the neuronal library "GLT1b." Preliminary LM and EM immunocytochemical studies have shown that GLT1b is localized to neurons as well as astrocytes in the forebrain. In addition, GLT1b, but not GLT1a, has a PDZ-domain interaction consensus sequence at its C-terminal. The hypothesis motivating this project is that GLT1b is an important neuronal transporter, and that this variant form has interactions through its C-terminal with other proteins that are functionally important and not available to GLT1a. The specific aims of this project are to: 1. Compare the expression of GLT1a & b in neuronal cultures and in the brain. The hypothesis is that GLT1b expression accounts for the widespread presence of mRNA for GLT1 in neurons in the brain. 2. Characterize interactors found in a yeast two-hybrid screen with GLT1b. The hypothesis is that GLT1b interacts with one or more PDZ domain containing proteins. 3. Characterize the effect of protein interactors on the function of GLT1a & b. The hypothesis is that the function of variant forms of GLT1 will be influenced by interactions with other proteins.