Maintaining soluble protein homeostasis between nuclear and cytoplasmic compartments across mitosis

The nuclear envelope (NE) is central to the architecture of eukaryotic cells, both as a physical barrier separating the nucleus from the cytoplasm and as gate-keeper of selective transport between them. However, in open mitosis, the NE fragments to allow for spindle formation and segregation of chromosomes, resulting in intermixing of nuclear and cytoplasmic soluble fractions. Recent studies have shed new light on the mechanisms driving reinstatement of soluble proteome homeostasis following NE reformation in daughter cells. Here, we pro-vide an overview of how mitotic cells confront this challenge to ensure continuity of basic cellular functions across generations and elaborate on the implications for the proteasome - a macromolecular machine that functions in both cytoplas-mic and nuclear compartments.

Automated summary

The nuclear envelope plays a crucial role in eukaryotic cells as a physical barrier and gate-keeper for selective transport between the nucleus and cytoplasm. During open mitosis, the nuclear envelope fragments to allow spindle formation and chromosome segregation, leading to mixing of nuclear and cytoplasmic soluble fractions. Recent studies have revealed the mechanisms behind the restoration of soluble proteome homeostasis following nuclear envelope reformation in daughter cells. This article provides an overview of how mitotic cells overcome this challenge to ensure continuity of cellular functions and discusses its implications for the proteasome, which functions in both the cytoplasmic and nuclear compartments.