Selective ribosome profiling reveals a role for SecB in the co-translational inner membrane protein biogenesis

The chaperone SecB has been implicated in de novo protein folding and translocation across the membrane, but it remains unclear which nascent polypeptides SecB binds, when during translation SecB acts, how SecB function is coordinated with other chaperones and targeting factors, and how polypeptide...

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Detalles Bibliográficos
Autores: Eismann, Lena, Fijalkowski, Igor, Galmozzi, Carla V., Koubek, Jiří, Tippmann, Frank, Van Damme, Petra, Kramer, Günter
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/307130
Acceso en línea:http://hdl.handle.net/10261/307130
https://api.elsevier.com/content/abstract/scopus_id/85143571215
Access Level:acceso abierto
Palabra clave:Trigger factor
CP
Molecular biology
SecB
Chaperone
Compartment-specific ribosome profiling
Membrane insertion
Proteostasis
Selective ribosome profiling
Signal recognition particle
Translocation
Descripción
Sumario:The chaperone SecB has been implicated in de novo protein folding and translocation across the membrane, but it remains unclear which nascent polypeptides SecB binds, when during translation SecB acts, how SecB function is coordinated with other chaperones and targeting factors, and how polypeptide engagement contributes to protein biogenesis. Using selective ribosome profiling, we show that SecB binds many nascent cytoplasmic and translocated proteins generally late during translation and controlled by the chaperone trigger factor. Revealing an uncharted role in co-translational translocation, inner membrane proteins (IMPs) are the most prominent nascent SecB interactors. Unlike other substrates, IMPs are bound early during translation, following the membrane targeting by the signal recognition particle. SecB remains bound until translation is terminated, and contributes to membrane insertion. Our study establishes a role of SecB in the co-translational maturation of proteins from all cellular compartments and functionally implicates cytosolic chaperones in membrane protein biogenesis.