• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Structural and Functional Features of the Polyglutamine-Expanded Androgen Receptor in Spinal and Bulbar Muscular Atrophy.
【24h】

Structural and Functional Features of the Polyglutamine-Expanded Androgen Receptor in Spinal and Bulbar Muscular Atrophy.

机译：脊柱和后壁肌萎缩症中聚谷氨酰胺扩展的雄激素受体的结构和功能特征。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Polyglutamine-repeat disorders are part of a larger family of neurodegenerative diseases characterized by protein misfolding and aggregation. A leading hypothesis for many polyglutamine proteins is that proteolysis of the mutant protein produces a polyglutamine-containing fragment that is most toxic in a soluble form, prior to fragment accumulation into insoluble inclusions. Despite this view, recent data demonstrate that the native function of the protein affected by polyglutamine-expansion is important in disease. The focus of this work was to further our understanding of the relationship between native AR function, aggregation, and toxicity using cell and mouse models of SBMA that express the full-length polyglutamine-expanded AR protein.;To investigate the role of native AR function in protein aggregation, we developed sensitive biochemical assays in order to compare the temporal formation of soluble and insoluble aggregation species with that of nuclear inclusions and motor neuron degeneration. We demonstrated that soluble conformations of polyglutamine-expanded AR aggregation species form early in the course of hormone treatment and contain the full-length polyglutamine-expanded AR protein; proteasome-mediated cleavage to an amino-terminal fragment was only observed after the formation of insoluble protein species and nuclear inclusions, suggesting that early aggregation events precede detectable AR proteolysis. Additionally, soluble, full-length polyglutamine-expanded AR aggregation species were demonstrated to bind the conformation-specific and toxicity-predicting antibody, 3B5H10. We found that soluble 3B5H10-reactive aggregation species exist in low-density conformations and are larger by atomic force microscopy, suggesting that they may be less compact than later-stage insoluble aggregates. We further showed that these species exist in vivo and demonstrated correlations with toxicity in vitro, using a cell line that expresses a protective mutation of the polyglutamine-expanded AR in an otherwise toxic native functional domain.;To further explore the relationship between AR native function and toxicity, we investigated the role of AR transactivation, a major native function of the AR, in SBMA. Using 2 different cell models of SBMA, we demonstrated that cells expressing DNA-binding deficient polyglutamine-expanded AR still display hormone-dependent toxicity, suggesting that AR transcriptional activity is not absolutely necessary for the toxicity observed in SBMA.;Taken together, the data presented in this thesis contribute to a novel model of aggregation in SBMA, based on the incorporation of full-length polyglutamine-expanded AR protein into early aggregation species, with unique structural features.
机译：多谷氨酰胺重复性疾病是神经退行性疾病大家族的一部分，其特征在于蛋白质错误折叠和聚集。许多聚谷氨酰胺蛋白的主要假设是突变蛋白的蛋白水解产生了含聚谷氨酰胺的片段，该片段在溶解成不溶性内含物之前以可溶形式最具毒性。尽管有这种观点，最近的数据表明受聚谷氨酰胺扩展影响的蛋白质的天然功能在疾病中很重要。这项工作的重点是使用表达全长聚谷氨酰胺扩增的AR蛋白的SBMA细胞模型和小鼠模型，进一步了解天然AR功能，聚集和毒性之间的关系。在蛋白质聚集中，我们开发了灵敏的生化测定法，以比较可溶性和不溶性聚集物种与核内含物和运动神经元变性的时间形成。我们证明了在激素治疗的过程中，聚谷氨酰胺扩增的AR聚集物的可溶性构象形成了早期，并且包含全长的聚谷氨酰胺扩增的AR蛋白。蛋白酶体介导的对氨基末端片段的切割仅在形成不溶性蛋白质和核内含物后才观察到，表明早期聚集事件先于可检测的AR蛋白水解。此外，可溶的，全长的聚谷氨酰胺扩展的AR聚集物质被证明与构象特异性和毒性预测抗体3B5H10结合。我们发现，可溶性3B5H10反应性聚集物种存在于低密度构象中，并且通过原子力显微镜观察其体积更大，这表明它们可能比后期的不溶性聚集体紧凑。我们进一步证明了这些物种存在于体内，并通过在其他有毒的天然功能域中表达聚谷氨酰胺扩增的AR的保护性突变的细胞系，证明了其与体外毒性的相关性;以进一步探讨AR天然功能之间的关系和毒性，我们研究了AR反式激活（AR的主要天然功能）在SBMA中的作用。使用SBMA的2种不同细胞模型，我们证明了表达DNA结合缺陷的聚谷氨酰胺扩增的AR的细胞仍然显示激素依赖性毒性，这表明AR转录活性并不是SBMA中观察到的毒性绝对必要的。本文将全长聚谷氨酰胺扩增的AR蛋白掺入具有独特结构特征的早期聚集物种中，为SBMA中的新型聚集模型做出了贡献。

著录项

  • 作者

    Berger, Tamar R.;

  • 作者单位

    Thomas Jefferson University.;

  • 授予单位 Thomas Jefferson University.;
  • 学科 Neurosciences.;Biochemistry.
  • 学位 Ph.D.
  • 年度 2016
  • 页码 236 p.
  • 总页数 236
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 财务管理、经济核算;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号