Cold shock induction of RNase R and its role in the maturation of the quality control mediator SsrA/tmRNA.
In this paper we show that RNase R is a cold shock protein that is induced seven- to eightfold by cold shock and that its expression is tightly regulated by temperature. Transcriptional studies reveal that the rnr gene is co-transcribed with flanking genes as an operon induced under cold shock. The induction of RNase R levels is mainly a result of the stabilization of the rnr transcripts. The transient stability of the rnr transcripts is shown to be regulated by PNPase at the end of the acclimation phase. Studies with an rnr mutant revealed a cold-shock phenotype showing that RNase R contributes to growth at low temperatures. We have shown that RNase R can be involved in the maturation of SsrA/tmRNA, an important small stable RNA involved in protein tagging and ribosome rescue. The wide biological significance of RNase R regarding adaptation to cold shock and its involvement in RNA surveillance, protein quality control and pathogenesis is discussed.
Cairrão
Fátima
F
Instituto Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apt 127, 2781-901 Oeiras, Portugal.
Cruz
Ana
A
Mori
Hiroyuki
H
Arraiano
Cecília Maria
CM
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003080:Cold Temperature; D004790:Enzyme Induction; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D005095:Exoribonucleases / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D009876:Operon; D010641:Phenotype; D011117:Polyribonucleotide Nucleotidyltransferase / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D020871:RNA Stability; D012329:RNA, Bacterial / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; C489683:rnr protein, E coli; C096222:tmRNA; C077231:VacB protein, Shigella flexneri; D012343:RNA, Transfer; D011117:Polyribonucleotide Nucleotidyltransferase; D005095:Exoribonucleases