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Göteborgs universitets publikationer

Decline in ribosomal fidelity contributes to the accumulation and stabilization of the master stress response regulator sigma S upon carbon starvation

Författare och institution:
Åsa Fredriksson (Institutionen för cell- och molekylärbiologi); Manuel Ballesteros (Institutionen för cell- och molekylärbiologi); Celeste N. Peterson (-); Örjan Persson (Institutionen för cell- och molekylärbiologi); Thomas J. Silhavy (-); Thomas Nyström (Institutionen för cell- och molekylärbiologi)
Publicerad i:
Genes & Development, 21 ( 7 ) s. 862-874
Artikel, refereegranskad vetenskaplig
Sammanfattning (abstract):
The {sigma}S subunit of RNA polymerase is a master regulator of Escherichia coli that retards cellular senescence and bestows cells with general stress protective functions during growth arrest. We show that mutations and drugs triggering translational errors elevate {sigma}S levels and stability. Furthermore, mutations enhancing translational fidelity attenuate induction of the rpoS regulon and prevent stabilization of {sigma}S upon carbon starvation. Destabilization of {sigma}S by increased proofreading requires the presence of the {sigma}S recognition factor SprE (RssB) and the ClpXP protease. The data further suggest that {sigma}S becomes stabilized upon starvation as a result of ClpP sequestration and this sequestration is enhanced by oxidative modifications of aberrant proteins produced by erroneous translation. ClpP overproduction counteracted starvation-induced stabilization of {sigma}S, whereas overproduction of a ClpXP substrate (ssrA-tagged GFP) stabilized {sigma}S in exponentially growing cells. We present a model for the sequence of events leading to the accumulation and activation of {sigma}S upon carbon starvation, which are linked to alterations in both ribosomal fidelity and efficiency.
Ämne (baseras på Högskoleverkets indelning av forskningsämnen):
Biologiska vetenskaper
Escherichia coli, stationary phase, RpoS, SprE, rpsL, ClpP, protein oxidation
Postens nummer:
Posten skapad:
2007-03-12 08:31
Posten ändrad:
2011-01-20 10:00

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