Transcription termination factor Rho and microbial phenotypic heterogeneity
Résumé
Populations of genetically identical microorganisms exhibit high degree of cell-to-cell phenotypic diversity
even when grown in uniform environmental conditions. Heterogeneity is a genetically determined trait, which ensures bacterial adaptation and survival in the ever changing environmental conditions. Fluctuations in gene expression (noise) at the level of transcription initiation largely contribute to cell-to-cell variability within population. Not surprisingly, the analyses of the mechanisms driving phenotypic
heterogeneity are mainly focused on the activity of promoters and transcriptional factors. Less attention is
currently given to a role of intrinsic and factor-dependent transcription terminators. Here, we discuss recent advances in understanding the regulatory role of the multi-functional transcription termination factor Rho, the major inhibitor of
pervasive transcription in bacteria and the emerging global
regulator of gene expression. We propose that termination
activity of Rho might be among the mechanisms by which
cells manage the intensity of transcriptional noise, thus
affecting population heterogeneity.