Force-regulated chaperone activity of BiP/ERdj3 is opposite to their homologs DnaK/DnaJ.
Protein Sci
; 33(7): e5068, 2024 Jul.
Article
en En
| MEDLINE
| ID: mdl-38864739
ABSTRACT
Polypeptide chains experience mechanical tension while translocating through cellular tunnels, which are subsequently folded by molecular chaperones. However, interactions between tunnel-associated chaperones and these emerging polypeptides under force is not completely understood. Our investigation focused on mechanical chaperone activity of two tunnel-associated chaperones, BiP and ERdj3 both with and without mechanical constraints and comparing them with their cytoplasmic homologs DnaK and DnaJ. While BiP/ERdj3 have been observed to exhibit robust foldase activity under force, DnaK/DnaJ showed holdase function. Importantly, the tunnel-associated chaperones (BiP/ERdj3) transitioned to a holdase state in the absence of force, indicating a force-dependent chaperone behavior. This chaperone-driven folding event in the tunnel generated an additional mechanical energy of up to 54 zJ, potentially aiding protein translocation. Our findings align with strain theory, where chaperones with higher intrinsic deformability act as mechanical foldases (BiP, ERdj3), while those with lower deformability serve as holdases (DnaK and DnaJ). This study thus elucidates the differential mechanically regulated chaperoning activity and introduces a novel perspective on co-translocational protein folding.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas HSP70 de Choque Térmico
/
Proteínas de Escherichia coli
/
Proteínas del Choque Térmico HSP40
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Proteínas de Choque Térmico
Idioma:
En
Revista:
Protein Sci
Asunto de la revista:
BIOQUIMICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
India
Pais de publicación:
Estados Unidos