A cytosolic surveillance mechanism activates the mitochondrial UPR.
Nature
; 618(7966): 849-854, 2023 Jun.
Article
em En
| MEDLINE
| ID: mdl-37286597
ABSTRACT
The mitochondrial unfolded protein response (UPRmt) is essential to safeguard mitochondria from proteotoxic damage by activating a dedicated transcriptional response in the nucleus to restore proteostasis1,2. Yet, it remains unclear how the information on mitochondria misfolding stress (MMS) is signalled to the nucleus as part of the human UPRmt (refs. 3,4). Here, we show that UPRmt signalling is driven by the release of two individual signals in the cytosol-mitochondrial reactive oxygen species (mtROS) and accumulation of mitochondrial protein precursors in the cytosol (c-mtProt). Combining proteomics and genetic approaches, we identified that MMS causes the release of mtROS into the cytosol. In parallel, MMS leads to mitochondrial protein import defects causing c-mtProt accumulation. Both signals integrate to activate the UPRmt; released mtROS oxidize the cytosolic HSP40 protein DNAJA1, which leads to enhanced recruitment of cytosolic HSP70 to c-mtProt. Consequently, HSP70 releases HSF1, which translocates to the nucleus and activates transcription of UPRmt genes. Together, we identify a highly controlled cytosolic surveillance mechanism that integrates independent mitochondrial stress signals to initiate the UPRmt. These observations reveal a link between mitochondrial and cytosolic proteostasis and provide molecular insight into UPRmt signalling in human cells.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Citosol
/
Resposta a Proteínas não Dobradas
/
Estresse Proteotóxico
/
Mitocôndrias
Tipo de estudo:
Screening_studies
Limite:
Humans
Idioma:
En
Revista:
Nature
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Alemanha