Mechanisms by which Bok binds to IP3Rs and regulates mitochondrial dynamics

Bok 与 IP3R 结合并调节线粒体动力学的机制

• 批准号: 10224261
• 负责人: Laura Szczesniak
• 金额: $ 5.1万
• 依托单位: UPSTATE MEDICAL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-03 至 2022-08-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224261
• 关键词: Apoptosis; Apoptotic; BCL-2 Protein; BCL2 gene; Binding; Binding Sites; Biological; CRISPR/Cas technology; Calcium; Calcium Channel; Cell Death; Cell physiology; Cells; Cerebral cortex; Data; Development; Disease; Embryo; Endoplasmic Reticulum; Family member; Fibroblasts; Functional disorder; Genes; Goals; Hippocampus (Brain); ITPR1 gene; Inositol; Investigation; Knock-out; Knockout Mice; Knowledge; Laboratories; Lead; Learning; Maintenance; Mammalian Cell; Mediating; Membrane; Metabolic Diseases; Mitochondria; Mitochondrial Proteins; Morphology; Mutagenesis; Nature; Neurodegenerative Disorders; Neurons; Organelles; Play; Process; Property; Protein Family; Proteins; Publications; Reporting; Research; Role; Signal Transduction; Structure; Therapeutic; Tissues; Work; age related neurodegeneration; design; insight; member; mitochondrial dysfunction; multicatalytic endopeptidase complex; novel; receptor

PROJECT SUMMARY The Bcl-2 protein family is a group of proteins that plays an important role in intrinsic apoptosis and includes the protein Bok. While many members of the Bcl-2 protein family have been thoroughly studied, Bok is a very poorly understood protein, with pro-, anti-, and non-apoptotic properties reported. Our lab has shown previously that Bok is constitutively bound to inositol 1,4,5-trisphosphate receptors (IP3Rs), which are tetrameric calcium channels found in the endoplasmic reticulum (ER) membrane of mammalian cells. While other Bcl-2 protein family members have been reported to interact with IP3Rs, the Bok-IP3R interaction is much more efficient, with essentially all Bok bound to IP3Rs. We have shown that Bok interacts with IP3Rs in all tissues, including cerebral cortex and hippocampus. Additionally, we have discovered that Bok protects IP3Rs from proteolytic cleavage, and in the absence of IP3Rs, Bok is ubiquitinated and rapidly degraded by the proteasome. Recent data has shown that Bok promotes mitochondrial fusion, and Bok knock-out mouse embryonic fibroblast cells have more fragmented mitochondria compared to control cells. Since Bok is expressed highly in hippocampal neurons, and mitochondrial dysfunction can often lead to neurodegenerative disease, it is possible that Bok plays a role in the development of neurodegenerative disease. Therefore, the current aims of this study are 1) to determine how ER-bound Bok promotes mitochondrial fusion activity and 2) to define the exact nature of the Bok-IP3R binding interface. Results from these aims will fill our current gaps in knowledge regarding Bok’s role in the cell and the Bok-IP3R interaction, and can contribute to our overall knowledge of the various functions of the Bcl-2 protein family.

项目摘要 Bcl-2蛋白家族是一组在内源性凋亡中起重要作用的蛋白质， 包括Bok蛋白。虽然Bcl-2蛋白家族的许多成员已经被彻底研究， 虽然已经研究了Bok，但是Bok是一种非常不了解的蛋白质，其具有促凋亡、抗凋亡和非凋亡特性。 我们的实验室以前已经表明，博克是组成性结合肌醇1，4，5-三磷酸受体 （IP 3R），其是在小鼠的内质网（ER）膜中发现的四聚体钙通道。 哺乳动物细胞虽然其他Bcl-2蛋白家族成员已被报道与IP 3R相互作用， Bok-IP 3R相互作用更加有效，基本上所有的Bok都与IP 3R结合。我们已经表明 Bok与所有组织中的IP 3R相互作用，包括大脑皮层和海马。另外我们 已经发现Bok保护IP 3R免受蛋白水解切割，并且在IP 3R不存在的情况下，Bok 被蛋白酶体泛素化并迅速降解。最近的数据显示，博克促进了 线粒体融合，与Bok基因敲除小鼠胚胎成纤维细胞相比， 与对照细胞相比。由于Bok在海马神经元中高度表达， 线粒体功能障碍通常会导致神经退行性疾病，Bok可能在其中起着重要作用。 在神经退行性疾病发展中的作用。因此，本研究目前的目的是1） 以确定ER结合的Bok如何促进线粒体融合活性和2）确定确切的 Bok-IP 3R绑定接口的性质。这些目标的结果将填补我们目前在知识上的空白 关于Bok在细胞中的作用和Bok-IP 3 R相互作用，并可以为我们的整体研究做出贡献 了解Bcl-2蛋白家族的各种功能。