BAX Activation and Oligomerization

BAX 活化和寡聚化

• 批准号: 8978981
• 负责人: Mahmoud Nasr
• 金额: $ 5.42万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-07 至 2017-07-06
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8978981
• 关键词: Affinity; Apoptosis; Apoptotic; Autoimmune Diseases; BCL-2 Protein; BCL2 gene; BCL2L11 gene; Binding; Cell Death; Cells; Complex; Cytochromes; Cytosol; DNA; Data; Deuterium; Development; Disease; Environment; Event; Goals; Hydrogen; Laboratories; Lead; Liposomes; Malignant Neoplasms; Maps; Mass Spectrum Analysis; Mediating; Membrane; Mitochondria; Modeling; Molecular; Molecular Conformation; Nature; Neurodegenerative Disorders; Outer Mitochondrial Membrane; Phospholipids; Physiological; Play; Process; Protein Family; Protein translocation; Proteins; Reporting; Research; Role; Stimulus; Structure; Technology; Therapeutic Agents; Therapeutic Intervention; Voltage-Dependent Anion Channel; Voltage-Dependent_Anion_Channel-1; X-Ray Crystallography; biophysical techniques; dimer; member; nanodisk; protein activation; protein complex; protein structure; public health relevance; reconstitution; release factor; three dimensional structure

 DESCRIPTION (provided by applicant): BCL-2 associated X protein (BAX) is a proapoptotic member of the BCL-2 protein family, which plays an essential role in triggering cell commitment to apoptosis. Depending on the physiological condition of the cell, BAX shuttles between soluble (inactive) and mitochondrial outer membrane-associated conformation(s). Upon activation by various apoptotic stimuli, BAX translocates to the mitochondrial outer membrane (MOM) and undergoes a set of conformational changes leading to protein oligomerization. Ultimately, oligomerization leads to assembly of pores through which apoptogenic factors, such as cytochrome C, are released from the mitochondrial inter- membrane space to the cytosol, thus initiating apoptosis. Despite extensive research in this field, the exact mechanism by which BAX mediates MOM permeabilization as well as the nature and structure of BAX-mediated pores remain elusive. Clarifying the structural transitions that drive BAX activation and pore formation may facilitate the development of therapeutic agents that can potentially be used to treat diseases with inadequate apoptosis, such as cancer, or excessive apoptosis such as neurodegenerative disorders. In Aim 1, we will attempt to solve the 3D structure for membrane-engaged BAX using mainly NMR among other biophysical techniques. We will also structurally characterize the BAX-mediated pore. Several reports have suggested that BAX interacts with voltage dependent anion channel 1 (VDAC-1), however the significance of this interaction is not clear. In Aim 2, we will pursue the structural characterization of the VDAC-1/BAX complex. Together these aims will help us better understand the mechanistic details of BAX-mediated apoptosis.

 描述（由申请人提供）：BCL-2相关X蛋白（BAX）是BCL-2蛋白家族的促凋亡成员，根据细胞的生理状况，BAX在触发细胞凋亡中发挥重要作用。在各种凋亡刺激激活后，BAX 在可溶性（无活性）和线粒体外膜相关构象之间穿梭，转位至线粒体外膜 (MOM) 并经历一系列过程。最终，寡聚化导致孔的组装，细胞色素C等凋亡因子通过孔从线粒体膜间空间释放到细胞质中，从而引发细胞凋亡。 BAX 介导 MOM 通透的确切机制以及 BAX 介导的孔的性质和结构仍然难以阐明驱动 BAX 活化和孔形成的结构转变。 可能有助于开发可用于治疗细胞凋亡不足的疾病（例如癌症）或细胞凋亡过度（例如神经退行性疾病）的治疗剂。在目标 1 中，我们将尝试主要使用膜接合 BAX 来解决 3D 结构。我们还将对 BAX 介导的孔的结构进行 NMR 表征，一些报告表明 BAX 与电压依赖性阴离子通道 1 (VDAC-1) 相互作用，但这种相互作用的意义尚不清楚。 2，我们将研究 VDAC-1/BAX 复合物的结构特征，这些目标将帮助我们更好地了解 BAX 介导的细胞凋亡的机制细节。