title: Elevation of RNase R in response to multiple stress conditions.
abstract: Cells respond to adverse environmental conditions by synthesizing new proteins or elevating the levels of pre-existing ones that are needed to cope with the particular stress situation. We show here that Escherichia coli RNase R, a processive 3'-to5'-exoribonuclease, is dramatically increased in response to a variety of different stress conditions. Elevation of RNase R activity by as much as 10-fold was observed in response to entry into stationary phase, starvation, and cold shock, and a approximately 3-fold increase was seen during growth in minimal medium compared with rich medium. The elevation in RNase R activity was associated primarily with an increase in RNase R protein. RNase R was previously implicated in quality control of rRNA and tRNA and in the decay of mRNAs with extensive secondary structure. Its dramatic increase under multiple stress conditions suggests extensive remodeling of structured RNA in response to the altered environment.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33101, USA.
authors.forename: Chenglu
authors.initials: C
authors.lastname: Chen
authors.forename: Murray P
authors.initials: MP
authors.lastname: Deutscher
mesh_terms: D015153:Blotting, Western; D002453:Cell Cycle; D003080:Cold Temperature; D003470:Culture Media / Q000494:pharmacology; D004722:Endoribonucleases / Q000096:biosynthesis* / Q000378:metabolism; D004777:Environment; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000502:physiology; D005095:Exoribonucleases; D005947:Glucose / Q000494:pharmacology; D006358:Hot Temperature; D015151:Immunoblotting; D012333:RNA, Messenger / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D012343:RNA, Transfer / Q000378:metabolism; D013696:Temperature; D013997:Time Factors; D015854:Up-Regulation
chemical_list: D003470:Culture Media; D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012343:RNA, Transfer; D004722:Endoribonucleases; D005095:Exoribonucleases; C080868:ribonuclease R; D005947:Glucose