Molecular basis of clathrin-mediated stabilization of microtubules for chromosome segregation

网格蛋白介导的染色体分离微管稳定的分子基础

• 批准号: 394694869
• 负责人: Dr. Alexander Bird, Ph.D.
• 金额: --
• 依托单位: Max-Planck-Institut für molekulare Physiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/394694869?language=en
• 关键词: Molecular; basis; clathrin; mediated; stabilization

The precise regulation of microtubule dynamics and stability during mitosis is critical for accurate chromosome segregation and genome stability. Indeed, the hyperstabilization of microtubules frequently observed in cancer cells during mitosis induces chromosome missegregation and chromosomal instability (CIN), important factors that drive tumour progression. Despite this knowledge, we continue to have a poor understanding of the players and mechanisms by which cells regulate microtubule stability during mitosis. Clathrin, widely known for its well-studied role as a vesicle coating protein for endocytosis and vesicle trafficking, has recently been shown to play an important yet independent role in microtubule stabilization during mitosis. Clathrin associates with the mitotic spindle and stabilizes microtubules required for efficient chromosome alignment. The mechanisms by which clathrin stabilizes microtubules, however, have remained elusive. Hence the overall objective of this proposal is to elucidate how clathrin and its mitotically-associated protein complex promotes microtubule stability. We have recently discovered a novel microtubule stabilizing protein, GTSE1, and identified its stabilization mechanism and the impact of its often-seen deregulation in cancer cells on CIN. Preliminary data suggests that clathrin may directly recruit GTSE1 to spindles in an analogous manner to clathrin-adaptor protein interactions: via clathrin adaptor binding sites within the N-terminal beta propeller of clathrin heavy chain and conserved adaptor-like motifs in GTSE1. This exciting finding has inspired this proposal, in which we aim to investigate the mechanisms and role of clathrin recruitment of GTSE1 to the spindle, the structural nature of the clathrin-stabilization complex on microtubules, and more broadly the contribution of clathrin-adaptor protein-like interactions to microtubule stability. With these studies we aspire to provide a mechanistic explanation of how clathrin stabilizes microtubules to ensure chromosome segregation, leading to deeper insights to the regulation of mitotic microtubule stability and its deregulation in cancer.

有丝分裂过程中微管动力学和稳定性的精确调节对于精确的染色体分离和基因组稳定性至关重要。事实上，在有丝分裂期间经常在癌细胞中观察到的微管的超稳定性诱导染色体错误分离和染色体不稳定性（CIN），这是驱动肿瘤进展的重要因素。尽管有这些知识，我们仍然对细胞在有丝分裂过程中调节微管稳定性的参与者和机制缺乏了解。网格蛋白，广泛了解其作为囊泡包被蛋白的内吞作用和囊泡运输的作用，最近已被证明在有丝分裂过程中微管稳定发挥重要而独立的作用。网格蛋白与有丝分裂纺锤体相关，并稳定有效染色体排列所需的微管。然而，网格蛋白稳定微管的机制仍然难以捉摸。因此，本提案的总体目标是阐明网格蛋白及其有丝分裂相关蛋白复合物如何促进微管稳定性。我们最近发现了一种新的微管稳定蛋白GTSE 1，并确定了其稳定机制及其在癌细胞中常见的失调对CIN的影响。初步数据表明，网格蛋白可以直接招募GTSE 1纺锤体以类似的方式网格蛋白衔接蛋白的相互作用：通过网格蛋白衔接结合位点内的N-末端β螺旋桨的网格蛋白重链和保守的衔接子样基序GTSE 1。这一令人兴奋的发现激发了这一提议，我们的目标是研究网格蛋白招募GTSE 1到纺锤体的机制和作用，微管上网格蛋白稳定复合物的结构性质，以及更广泛地网格蛋白-适配蛋白样相互作用对微管稳定性的贡献。通过这些研究，我们希望提供一个机制解释网格蛋白如何稳定微管，以确保染色体分离，从而更深入地了解有丝分裂微管稳定性的调节及其在癌症中的失调。

项目成果

Clathrin’s adaptor interaction sites are repurposed to stabilize microtubules during mitosis

• DOI: 10.1083/jcb.201907083
• 发表时间: 2019-08
• 期刊: The Journal of Cell Biology
• 作者: Arnaud Rondelet;Yu-Chih Lin;Divya Singh;A. T. Porfetye;H. C. Thakur;Andreas Hecker;Pia Brinkert;Nadine Schmidt;Shweta Bendre;Franziska Müller;Per O. Widlund;Tanja Bange;M. Hiller;I. Vetter;A. Bird