AUTHOR=Cianciulli Sesso Anastasia , Resch Armin , Moll Isabella , Bläsi Udo , Sonnleitner Elisabeth 

TITLE=The FinO/ProQ-like protein PA2582 impacts antimicrobial resistance in Pseudomonas aeruginosa

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1422742

DOI=10.3389/fmicb.2024.1422742

ISSN=1664-302X

ABSTRACT=<p>Bacteria employ small regulatory RNAs (sRNA) and/or RNA binding proteins (RBPs) to respond to environmental cues. In <italic>Enterobacteriaceae</italic>, the FinO-domain containing RBP ProQ associates with numerous sRNAs and mRNAs, impacts sRNA-mediated riboregulation or mRNA stability by binding to 5′- or 3′-untranslated regions as well as to internal stem loop structures. Global RNA-protein interaction studies and sequence comparisons identified a ProQ-like homolog (PA2582/ProQ<italic><sub>Pae</sub></italic>) in <italic>Pseudomonas aeruginosa</italic> (<italic>Pae</italic>). To address the function of ProQ<italic><sub>Pae</sub></italic>, at first a comparative transcriptome analysis of the <italic>Pae</italic> strains PAO1 and PAO1Δ<italic>proQ</italic> was performed. This study revealed more than 100 differentially abundant transcripts, affecting a variety of cellular functions. Among these transcripts were <italic>pprA</italic> and <italic>pprB</italic>, encoding the PprA/PprB two component system, <italic>psrA</italic>, encoding a transcriptional activator of <italic>pprB</italic>, and <italic>oprI</italic>, encoding the outer membrane protein OprI. RNA co-purification experiments with Strep-tagged <italic>Pae</italic> ProQ protein corroborated an association of ProQ<italic><sub>Pae</sub></italic> with these transcripts. In accordance with the up-regulation of the <italic>psrA</italic>, <italic>pprA</italic>, and <italic>pprB</italic> genes in strain PAO1Δ<italic>proQ</italic> a phenotypic analysis revealed an increased susceptibility toward the aminoglycosides tobramycin and gentamicin in biofilms. Conversely, the observed down-regulation of the <italic>oprI</italic> gene in PAO1Δ<italic>proQ</italic> could be reconciled with a decreased susceptibility toward the synthetic cationic antimicrobial peptide GW-Q6. Taken together, these studies revealed that ProQ<italic><sub>Pae</sub></italic> is an RBP that impacts antimicrobial resistance in <italic>Pae</italic>.</p>