The power duo: how the interplay between nucleoid-associated proteins
and small non-coding RNAs orchestrates the cellular regulatory symphony
Abstract
In bacteria, the regulation of gene expression involves complex networks
that integrate both transcriptional and post-transcriptional mechanisms.
At the transcriptional level, nucleoid-associated proteins (NAPs) such
as H-NS, HU, Lrp, IHF, Fis and Hfq are key players as they not only
compact bacterial DNA, but also regulate transcription. Small non-coding
RNAs (sRNAs), on the other hand, affect bacterial gene expression
post-transcriptionally by base pairing with the target mRNA.
Interestingly, certain NAPs also influence the function of sRNAs and,
conversely, sRNAs themselves can modulate the activity of NAPs, creating
a complex bidirectional regulatory network. Here, we summarise the
current knowledge of the major NAPs, focusing on the specific role of
Hfq. Examples of the regulation of NAPs by sRNAs, the regulation of
sRNAs by NAPs and the role of sRNAs in nucleoid structuring are also
discussed. This review focuses on the cross-talk between NAPs and sRNAs
in an attempt to understand how the interplay between cellular proteins
and regulatory RNAs contributes to the fine-tuning regulation of
bacterial gene expression.