Contractile acto-myosin network on nuclear envelope remnants positions human chromosomes for mitosis

eLife

Zuojun Yue¹  John K Eykelenboom¹  Tomoyuki U Tanaka¹  Alexander JR Booth¹  GW Gant Luxton²  Helfrid Hochegger³  Tom Stiff³ 

[1] Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom;College of Biological Sciences, University of Minnesota, Minneapolis, United States;Genome Damage and Stability Centre, University of Sussex, Brighton, United Kingdom;

关键词: chromosomes;    mitotic spindle;    acto-myosin;    nuclear envelope;    LINC complex;    human cells;   

DOI  :  10.7554/eLife.46902

来源: DOAJ

【 摘 要 】

To ensure proper segregation during mitosis, chromosomes must be efficiently captured by spindle microtubules and subsequently aligned on the mitotic spindle. The efficacy of chromosome interaction with the spindle can be influenced by how widely chromosomes are scattered in space. Here, we quantify chromosome-scattering volume (CSV) and find that it is reduced soon after nuclear envelope breakdown (NEBD) in human cells. The CSV reduction occurs primarily independently of microtubules and is therefore not an outcome of interactions between chromosomes and the spindle. We find that, prior to NEBD, an acto-myosin network is assembled in a LINC complex-dependent manner on the cytoplasmic surface of the nuclear envelope. This acto-myosin network remains on nuclear envelope remnants soon after NEBD, and its myosin-II-mediated contraction reduces CSV and facilitates timely chromosome congression and correct segregation. Thus, we find a novel mechanism that positions chromosomes in early mitosis to ensure efficient and correct chromosome–spindle interactions.

【 授权许可】

Unknown