RRC ID 35280
Author Otsuka Y, Miki K, Koga M, Katayama N, Morimoto W, Takahashi Y, Yonesaki T.
Title IscR regulates RNase LS activity by repressing rnlA transcription.
Journal Genetics
Abstract The Escherichia coli endoribonuclease LS was originally identified as a potential antagonist of bacteriophage T4. When the T4 dmd gene is defective, RNase LS cleaves T4 mRNAs and antagonizes T4 reproduction. This RNase also plays an important role in RNA metabolisms in E. coli. rnlA is an essential gene for RNase LS activity, but the transcriptional regulation of this gene remains to be elucidated. An Fe-S cluster protein, IscR, acts as a transcription factor and controls the expression of genes that are necessary for Fe-S cluster biogenesis. Here, we report that overexpression of IscR suppressed RNase LS activity, causing the loss of antagonist activity against phage T4. This suppressive effect did not require the ligation of Fe-S cluster into IscR. beta-Galactosidase reporter assays showed that transcription from an rnlA promoter increased in iscR-deleted cells compared to wild-type cells, and gel-mobility shift assays revealed specific binding of IscR to the rnlA promoter region. RT-PCR analysis demonstrated that endogenous rnlA mRNA was reduced by overexpression of IscR and increased by deletion of iscR. From these results, we conclude that IscR negatively regulates transcription of rnlA and represses RNase LS activity.
Volume 185(3)
Pages 823-30
Published 2010-7-1
DOI 10.1534/genetics.110.114462
PII genetics.110.114462
PMID 20421606
PMC PMC2907204
MeSH Blotting, Western Electrophoretic Mobility Shift Assay Escherichia coli / genetics* Escherichia coli / metabolism Escherichia coli Proteins / genetics* Escherichia coli Proteins / metabolism* Gene Expression Regulation, Bacterial* Iron-Sulfur Proteins / genetics Iron-Sulfur Proteins / metabolism Promoter Regions, Genetic / genetics RNA, Messenger / genetics Repressor Proteins / genetics Repressor Proteins / metabolism* Reverse Transcriptase Polymerase Chain Reaction Ribonucleases / genetics* Ribonucleases / metabolism Transcription Factors / genetics Transcription Factors / metabolism* Transcription Initiation Site Transcription, Genetic* beta-Galactosidase
IF 4.015
Times Cited 12
Prokaryotes E. coli JW2515-KC