Mechanisms of Golgi Vesiculation during Mitosis

有丝分裂期间高尔基体形成水泡的机制

基本信息

批准号：
7260190
负责人：
VIVEK MALHOTRA
金额：
$ 34.85万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
1999
资助国家：
美国
起止时间：
1999-02-01 至 2008-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7260190
关键词：
Address Antimitotic Agents Binding C-terminal Cell Cycle Cell Cycle Checkpoint Cells Class Collection Dimensions Drosophila genome Elements Endoplasmic Reticulum Enzymes Event G-Protein-Coupled Receptors Genome Golgi Apparatus Guanosine Triphosphate Phosphohydrolases Hand Homologous Gene Human Libraries Lipase MAP Kinase Gene MAP2K1 gene Mammalian Cell Membrane Membrane Proteins Mitogen-Activated Protein Kinases Mitosis Mitotic Mitotic spindle Molecular Motors Numbers Organelles Pathway interactions Phosphoric Monoester Hydrolases Phosphorylation Phosphotransferases Process Protein Binding Protein Dephosphorylation Protein Isoforms Proteins RNA Splicing Recruitment Activity Regulation Reporting Research Personnel Role Screening procedure Signal Transduction Testing Variant Vesicle Work daughter cell human PLK1 protein novel numb protein prevent programs transmission process

项目摘要

DESCRIPTION (provided by applicant): The pericentriolar inter connected stacks of Golgi cisternae are fragmented in mitotic mammalian cells. Why do these membranes undergo such a drastic change in their organization and by what mechanism? Do Golgi membranes fuse with the endoplasmic reticulum (ER) during mitosis and therefore use ER for their transmission into daughter cells? Our recent findings reveal that Golgi membranes do not fuse with the ER during mitosis. These findings resolve a long-standing controversy. We have found that inhibiting Golgi fragmentation prevents entry into mitosis. We have proposed the existence of a Golgi membrane specific cell-cycle checkpoint. We have found that kinases MEK1 and Polo like kinase (Plk); and Golgi associated proteins GRASP55 and GRASP65 are required for Golgi fragmentation. Our hypothesis is that MEK1 activates a novel spliced variant of ERK called ERK1c, which phosphorylates GRASP55 to disconnect Golgi stacks. This event occurs in G2 and it is necessary for entry into mitosis. Plk on the other hand, we suggest phosphorylates GRASP65. The phosphorylated GRASP65 recruits a novel protein called Gip (GRASP interacting protein) and this event is necessary for GRASP65 dependent regulation of spindle dynamics in mitosis. A new screen has revealed a number of proteins that regulate the dimensions of Golgi stacks and our hypothesis is that these proteins are modified (by phosphorylation/dephosphorylation) to reorganize Golgi membranes during mitosis. Finally, we are screening 5000 human enzymes (kinase, phosphatase, lipases, GTPases etc) to identify components that control, through the organization of Golgi apparatus, entry of cells into mitosis. Our findings will reveal the mechanism by which, cells duplicate their essential organelles during the cell cycle, and how Golgi membranes in turn through their organization, control mitotic entry

描述（由申请人提供）：在有丝分裂的哺乳动物细胞中，高尔基硫夫妇的丁香三醇相互连接的堆栈被碎片。为什么这些膜在其组织以及哪种机制中经历了如此巨大的变化？高尔基膜在有丝分裂过程中是否与内质网（ER）融合，从而将ER用于传播到子细胞中？我们最近的发现表明，高尔基膜在有丝分裂过程中不与ER融合。这些发现解决了长期的争议。我们发现，抑制高尔基体碎片可阻止进入有丝分裂。我们提出了高尔基膜特异性细胞周期检查点的存在。我们发现激酶Mek1和Polo像激酶（PLK）一样；高尔基体碎片所需的GOLGI蛋白GRASP55和GRASP65。我们的假设是MEK1激活了一种称为ERK1C的ERK的新型剪接变体，该变体将Grasp55磷酸化以断开连接Golgi堆栈。此事件发生在G2中，有必要进入有丝分裂。另一方面，我们建议磷酸化grasp65。磷酸化的GRASP65募集了一种称为GIP（GRASP相互作用蛋白）的新型蛋白质，对于GRASP65依赖的有丝分裂纺锤体动力学的调节是必不可少的。一个新的屏幕揭示了许多调节高尔基堆积尺寸的蛋白质，我们的假设是这些蛋白质经过修饰（通过磷酸化/去磷酸化）在有丝分裂过程中重新组织高尔基膜。最后，我们正在筛选5000种人类酶（激酶，磷酸酶，脂肪酶，GTPases等），以鉴定通过组织通过组织，将细胞进入有丝分裂的组件。我们的发现将揭示细胞在细胞周期中复制其必需细胞器的机制，以及高尔基膜如何通过其组织，控制有丝分裂进入