El Mouali Benomar, YoussefEsteva-Martínez, GuillemGarcía-Pedemonte, DavidBalsalobre Parra, Carlos2020-11-032020-11-032020-10-141664-302Xhttps://hdl.handle.net/2445/171714Post-transcriptional regulation mediated by regulatory small RNAs (sRNAs) has risen as a key player in fine-tuning gene expression in response to environmental stimuli. Here, we show that, in Salmonella enterica, the central metabolic regulator CRP-cAMP differentially regulates the sRNAs CsrB and CsrC in a growth phase-dependent manner. While CsrB expression remains unchanged during growth, CsrC displays a growth phase-dependent expression profile, being weakly expressed at the logarithmic growth phase and induced upon entry into stationary phase. We show that CRP-cAMP contributes to the expression pattern of CsrC by repressing its expression during the logarithmic growth phase. The CRP-cAMP mediated repression of CsrC is independent of SirA, a known transcriptional CsrB/CsrC activator. We further show that the sRNA Spot 42, which is derepressed in a Δcrp strain, upregulates CsrC during logarithmic growth. We propose a model where the growth-dependent regulation of CsrC is sustained by the CRP-cAMP-mediated repression of Spot 42. Together, our data point toward a differential regulation of the sRNAs CsrB and CsrC in response to environmental stimuli, leading to fine-tuning of gene expression via the sequestration of the RNA-binding protein CsrA.9 p.application/pdfengcc-by (c) El Mouali, Youssef et al., 2020http://creativecommons.org/licenses/by/3.0/esSalmonel·laExpressió gènicaSalmonellaGene expressioninfo:eu-repo/semantics/article7039262020-11-03info:eu-repo/semantics/openAccess1952150133162952