Tiling array study of MNNG treated Escherichia coli reveals a widespread transcriptional response

Sci Rep. 2013 Oct 25:3:3053. doi: 10.1038/srep03053.

Abstract

The alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) is known to trigger the adaptive response by inducing the ada-regulon - consisting of three DNA repair enzymes Ada, AlkB, AlkA and the enigmatic AidB. We have applied custom designed tiling arrays to study transcriptional changes in Escherichia coli following a MNNG challenge. Along with the expected upregulation of the adaptive response genes (ada, alkA and alkB), we identified a number of differentially expressed transcripts, both novel and annotated. This indicates a wider regulatory response than previously documented. There were 250 differentially-expressed and 2275 similarly-expressed unannotated transcripts. We found novel upregulation of several stress-induced transcripts, including the SOS inducible genes recN and tisAB, indicating a novel role for these genes in alkylation repair. Furthermore, the ada-regulon A and B boxes were found to be insufficient to explain the regulation of the adaptive response genes after MNNG exposure, suggesting that additional regulatory elements must be involved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Biological / genetics
  • Escherichia coli / drug effects*
  • Escherichia coli / genetics*
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial / drug effects*
  • Methylnitronitrosoguanidine / pharmacology*
  • Mutation
  • Operon
  • Promoter Regions, Genetic
  • RNA, Untranslated / genetics
  • Reproducibility of Results
  • Transcription, Genetic*
  • Transcriptome
  • Untranslated Regions

Substances

  • RNA, Untranslated
  • Untranslated Regions
  • Methylnitronitrosoguanidine