MAPPING THE BINDING SITE OF A SMALL MOLECULE INHIBITOR OF PROTEIN SECRETION

绘制蛋白质分泌小分子抑制剂的结合位点

• 批准号: 7957415
• 负责人: Jack Taunton
• 金额: $ 0.02万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7957415
• 关键词: Affinity; Binding Sites; Computer Retrieval of Information on Scientific Projects Database; Endoplasmic Reticulum; Funding; Grant; Institution; Integral Membrane Protein; Maps; Mass Spectrum Analysis; Membrane Proteins; Molecular; Molecular Conformation; N-terminal; Names; Peptide Signal Sequences; Protein Secretion; Proteins; Research; Research Design; Research Personnel; Resistance; Resources; Site; Source; United States National Institutes of Health; base; crosslink; inhibitor/antagonist; prevent; small molecule

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We recently identified a class of small molecules named "cotransins" that inactivate a subset of secreted and transmembrane proteins by blocking their cotranslational translocation into the endoplasmic reticulum. The N-terminal signal sequence of the secreted or transmembrane protein is sufficient to confer sensitivity or resistance to cotransin. However the molecular basis for this selectivity is unknown. Utilizing a cotransin photo-affinity probe, we identified Sec61alpha, a ten-pass integral membrane protein that forms the structural core of the Sec61 translocation channel, as the direct target of cotransin. Sec61 forms the channel through which all secreted and membrane proteins traverse during cotranslational translocation. We hypothesize that cotransin blocks translocation by stabilizing a closed conformation of the channel and by preventing a productive interaction between Sec61 and the translocating protein substrate. We propose to precisely map the photo-crosslinking site of cotransin using mass spectrometry. These studies are designed to decipher the precise mechanism by which cotransin inhibits cotranslational translocation and the molecular basis for its remarkable substrate selectivity.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们最近发现了一类名为“共转蛋白”的小分子，它通过阻断分泌蛋白和跨膜蛋白的共翻译易位进入内质网来抑制它们的亚类。 分泌或跨膜蛋白的N-末端信号序列足以赋予对共转运蛋白的敏感性或抗性。然而，这种选择性的分子基础是未知的。利用cotransin光亲和探针，我们确定了Sec 61 α，一个10次通过的完整的膜蛋白，形成了Sec 61易位通道的结构核心，作为cotransin的直接目标。Sec 61形成了所有分泌蛋白和膜蛋白在共翻译易位过程中穿过的通道。我们假设cotransin通过稳定通道的闭合构象和防止Sec 61与易位蛋白底物之间的有效相互作用来阻断易位。我们建议使用质谱法精确地绘制cotransin的光交联位点。这些研究旨在破译cotransin抑制共翻译易位的确切机制及其显着的底物选择性的分子基础。