VPS4 and CHMP7 release centromeres from the nuclear envelope for post-mitotic positioning in daughter nuclei

Abstract

Eukaryotic chromosomes occupy ordered configurations within the nucleus, an organization that must be re-established in daughter cells as the nuclear envelope reforms at the end of mitosis. The conserved enzyme VPS4 and ESCRT-III proteins mediate nuclear envelope reformation, yet their role in post-mitotic centromere positioning remains unclear. Here, we develop a chemical genetics approach to analyze the role of VPS4 in human cells. VPS4 inhibition prevents the clearance of CHMP7 from centromeres, which remain constrained in ring-like configurations established during mitosis. Without VPS4 activity, CHMP7, but not other ESCRT-III proteins, forms nuclear foci, nuclear envelope protein distribution is altered and inner nuclear membrane invaginations appear. Following these defects, DNA damage is observed in the vicinity of centromeres. Depletion of CHMP7, but not CHMP4B, suppresses this damage. We propose that VPS4-mediated turnover of CHMP7 releases centromeres from transient nuclear envelope contacts, ensuring their proper positioning after mitosis and maintaining genome integrity.