Acute Heat Stress Leads to Reversible Aggregation of Nuclear Proteins into Nucleolar Rings in Fission Yeast

Upon acute heat stress (HS), overall mRNA transcription, processing, and export are inhibited, leading to cell growth arrest. However, how cells turn off mRNA metabolism is not fully understood. Here, we show that acute HS results in the segregation and aggregation of multiple nuclear and nucleolar...

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Detalhes bibliográficos
Autores: Gallardo Palomo, Paola, Real-Caldero, Paula, Flor-Parra, Ignacio, Salas-Pino, Silvia, Daga, Rafael
Formato: artículo
Fecha de publicación:2020
País:España
Recursos:Universidad Pablo de Olavide (UPO)
Repositorio:RIO. Repositorio Institucional Olavide
Idioma:inglés
OAI Identifier:oai:rio.upo.es:10433/22772
Acesso em linha:https://hdl.handle.net/10433/22772
Access Level:acceso abierto
Palavra-chave:Heat stress response
Hsf1
Hsp104
Heat shock
Protein aggregation
Nucleolus
Nuclear pore complex
mRNA
Cell growth
Cell cycle
Descrição
Resumo:Upon acute heat stress (HS), overall mRNA transcription, processing, and export are inhibited, leading to cell growth arrest. However, how cells turn off mRNA metabolism is not fully understood. Here, we show that acute HS results in the segregation and aggregation of multiple nuclear and nucleolar proteins into ring-like structures located at the nucleolar periphery (nucleolar rings [NuRs]). NuRs sequester essential factors required for nuclear mRNA metabolism and nuclear pore complex function, as well as cell-cycle regulators. When cells are switched back to growing temperatures, NuRs disaggregate, and their components relocate to their functional environments in an Hsf1- and Hsp104-dependent manner, and concomitantly with the reinitiation of cell growth. These findings highlight the contribution of reversible protein aggregation to the inhibition of overall RNA-related activities in the nucleus and its functional relevance in the maintenance of cellular homeostasis during acute HS.