INTERACTIONS OF ANDROGEN RECEPTOR POLYGLUTAMINE TRACT

描述：（申请人摘要）脊髓和延髓肌萎缩症是 一种成人发病的神经退行性疾病，其特征是肌肉无力， 萎缩和肌束颤动。 它是一个不断壮大的家庭的成员 由 CAG 重复序列扩张引起的神经退行性疾病 在相关蛋白质编码内编码多聚谷氨酰胺束 序列。 我们的假设是，这些人中出现的神经变性 疾病是由编码蛋白质获得毒性功能引起的 由于多聚谷氨酰胺束的存在，并且这种毒性作用 由特定的蛋白质-蛋白质相互作用介导。 该项目旨在识别和分离蛋白质（及其相关的 与包含不同长度的雄激素受体相互作用的cDNA） 聚谷氨酰胺束。 这将通过两种方式完成。 首先，我们将使用一个 酵母双杂交系统识别与氨基相互作用的蛋白质 含有 24、45 或 66 个谷氨酰胺的雄激素受体末端区域 重复。 我们还将使用该系统来表征 多聚谷氨酰胺束长度上的相互作用。 我们期望对于 在致病过程中发挥作用的相互作用，应该是 在某种程度上受到谷氨酰胺重复序列长度的影响。 其次，我们将 使用放射性标记筛选 lambda 噬菌体表达库 纯化的不同重复长度的雄激素受体蛋白 细菌。 该方法将使我们能够差异化筛选库 使用包含不同长度的全长雄激素受体 聚谷氨酰胺束。 该系统也将被用于 通过以下任一方式鉴定的蛋白质结合特性的表征 方法。 最后，我们将描述蛋白质的生理相关性 使用细胞培养和通过这些筛选确定的相互作用 我们开发的转基因模型系统。 这些实验的结果应该可以提供对分子生物学的见解。 扩展的聚谷氨酰胺束对神经元有毒的机制， 并可能因此为治疗干预提供目标。 在 此外，了解神经元中雄激素受体蛋白的相互作用 将增加我们对类固醇激素受体在 这些细胞。

DESCRIPTION: (Applicant's abstract) Spinal and bulbar muscular atrophy is an adult-onset neurodegenerative disease characterized by muscle weakness, atrophy, and fasciculations. It is a member of a growing family of neurodegenerative diseases caused by the expansion of a CAG repeat that encodes a poly-glutamine tract within the associated protein coding sequence. Our hypothesis is that the neurodegeneration seen in these diseases results from the gain of a toxic function in the encoded protein due to the presence of the poly-glutamine tract, and that this toxic effect is mediated by specific protein-protein interactions. This project proposes to identify and isolate proteins (and their associated cDNAs) that interact with androgen receptor containing different length poly-glutamine tracts. This will be done in two ways. First, we will use a yeast two-hybrid system to identify proteins that interact with the amino terminal region of the androgen receptor containing 24, 45, or 66 glutamine repeats. We will also use this system to characterize the dependence of interactions on the length of the poly-glutamine tract. We expect that for an interaction to play a role in the pathogenic process, it should be affected in some way by the length of the glutamine repeat. Second, we will screen a lambda phage expression library using radioactively-labeled androgen receptor proteins of different repeat lengths purified from bacteria. This method will allow us to differentially screen libraries using full-length androgen receptor containing different length poly-glutamine tracts. This system will also be exploited for characterization of binding properties of proteins identified through either approach. Lastly, we will characterize the physiologic relevance of protein interactions identified through these screens using cell culture and transgenic model systems that we have developed. The results of these experiments should provide insights into the molecular mechanism by which expanded poly-glutamine tracts become toxic to neurons, and may consequently provide targets for therapeutic intervention. In addition, understanding androgen receptor protein interactions in neurons will increase our understanding of the role of steroid hormone receptors in these cells.