
細胞分裂時、細胞は核内に形成されたタンパク質凝集体を効率的に除去する。この除去プロセスはCdk1の不活性化と関連しており、プロテアソームの活性化を必要とするが、APC/Cには依存しない。


coremsg

Protein aggregates are spatially organized and regulated in cells to prevent deleterious effects of proteostatic stress. Misfolding of proteins in the ER result in aggregate formation, but how the aggregates are processed especially during cell division is not well understood. Here, we induced proteostatic stress and protein aggregation using a proteostasis reporter, which is prone to misfolding and aggregation in the ER. Unexpectedly, we detected solid-like protein aggregates deposited mainly in the nucleus and surrounded by the ER membrane. The membrane-bound aggregates were then cleared as cells progressed through mitosis and cytokinesis. Aggregate clearance was depended on Hsp70 family chaperones in the ER, particularly BiP, and proteasomal activity. The clearance culminates at mitotic exit and required cyclin-dependent kinase 1 (Cdk1) inactivation but was independent of the anaphase-promoting complex (APC/C). Thus, dividing cells have the capacity to clear protein aggregates to maintain proteostasis in the newly divided cells, which could have implications for human disease development and aging.

### Competing Interest Statement

The authors have declared no competing interest.

ER内のタンパク質凝集体は細胞分裂時に除去される