Your browser doesn't support javascript.
loading
De novo Synthesis and Assembly of rRNA into Ribosomal Subunits during Cold Acclimation in Escherichia coli.
Piersimoni, Lolita; Giangrossi, Mara; Marchi, Paolo; Brandi, Anna; Gualerzi, Claudio O; Pon, Cynthia L.
Afiliación
  • Piersimoni L; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy.
  • Giangrossi M; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy.
  • Marchi P; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy.
  • Brandi A; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy.
  • Gualerzi CO; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy. Electronic address: claudio.gualerzi@unicam.it.
  • Pon CL; Laboratory of Genetics, Department of Biosciences and Biotechnology, University of Camerino, 62032 Camerino, Italy.
J Mol Biol ; 428(8): 1558-73, 2016 Apr 24.
Article en En | MEDLINE | ID: mdl-26953262
During the cold adaptation that follows a cold stress, bacterial cells undergo many physiological changes and extensive reprogramming of their gene expression pattern. Bulk gene expression is drastically reduced, while a set of cold shock genes is selectively and transiently expressed. The initial stage of cold acclimation is characterized by the establishment of a stoichiometric imbalance of the translation initiation factors (IFs)/ribosomes ratio that contributes to the preferential translation of cold shock transcripts. Whereas de novo synthesis of the IFs following cold stress has been documented, nothing was known concerning the activity of the rrn operons during the cold acclimation period. In this work, we focus on the expression of the rrn operons and the fate of rRNA after temperature downshift. We demonstrate that in Escherichia coli, rRNA synthesis does not stop during the cold acclimation phase, but continues with greater contribution of the P2 compared to the P1 promoter and all seven rrn operons are active, although their expression levels change with respect to pre-stress conditions. Eight hours after the 37°â†’10 °C temperature downshift, the newly transcribed rRNA represents up to 20% of total rRNA and is preferentially found in the polysomes. However, with respect to the de novo synthesis of the IFs, both rRNA transcription and maturation are slowed down drastically by cold stress, thereby accounting in part for the stoichiometric imbalance of the IFs/ribosomes. Overall, our data indicate that new ribosomes, which are possibly suitable to function at low temperature, are slowly assembled during cold acclimation.
Asunto(s)
Palabras clave

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: ARN Bacteriano / ARN Ribosómico 16S / ARN Ribosómico 23S / Escherichia coli Idioma: En Revista: J Mol Biol Año: 2016 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Países Bajos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: ARN Bacteriano / ARN Ribosómico 16S / ARN Ribosómico 23S / Escherichia coli Idioma: En Revista: J Mol Biol Año: 2016 Tipo del documento: Article País de afiliación: Italia Pais de publicación: Países Bajos