YmdB: a stress-responsive ribonuclease-binding regulator of E. coli RNase III activity.
Genes Dev
; 22(24): 3497-508, 2008 Dec 15.
Article
in En
| MEDLINE
| ID: mdl-19141481
ABSTRACT
The broad cellular actions of RNase III family enzymes include ribosomal RNA (rRNA) processing, mRNA decay, and the generation of noncoding microRNAs in both prokaryotes and eukaryotes. Here we report that YmdB, an evolutionarily conserved 18.8-kDa protein of Escherichia coli of previously unknown function, is a regulator of RNase III cleavages. We show that YmdB functions by interacting with a site in the RNase III catalytic region, that expression of YmdB is transcriptionally activated by both cold-shock stress and the entry of cells into stationary phase, and that this activation requires the sigma-factor-encoding gene, rpoS. We discovered that down-regulation of RNase III activity occurs during both stresses and is dependent on YmdB production during cold shock; in contrast, stationary-phase regulation was unperturbed in YmdB-null mutant bacteria, indicating the existence of additional, YmdB-independent, factors that dynamically regulate RNase III actions during normal cell growth. Our results reveal the previously unsuspected role of ribonuclease-binding proteins in the regulation of RNase III activity.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ribonucleases
/
Stress, Physiological
/
Carrier Proteins
/
Gene Expression Regulation, Bacterial
/
Escherichia coli Proteins
/
Ribonuclease III
/
Escherichia coli
Language:
En
Journal:
Genes Dev
Journal subject:
BIOLOGIA MOLECULAR
Year:
2008
Document type:
Article
Affiliation country: