TY  - JOUR
AB  - Controlled RNA degradation is a crucial process in bacterial cell biology for maintaining proper transcriptome homeostasis and adaptation to changing environments. mRNA turnover in many Gram-positive bacteria involves a specialized ribonuclease called RNase J (RnJ). To date, however, nothing is known about this process in the diphtheria-causative pathogen Corynebacterium diphtheriae, nor is known the identity of this ribonuclease in this organism. Here, we report that C. diphtheriae DIP1463 encodes a predicted RnJ homolog, comprised of a conserved N-terminal beta-lactamase domain, followed by beta-CASP and C-terminal domains. A recombinant protein encompassing the beta-lactamase domain alone displays 5 '-exoribonuclease activity, which is abolished by alanine-substitution of the conserved catalytic residues His(186) and His(188). Intriguingly, deletion of DIP1463/rnj in C. diphtheriae reduces bacterial growth and generates cell shape abnormality with markedly augmented cell width. Comparative RNA-seq analysis revealed that RnJ controls a large regulon encoding many factors predicted to be involved in biosynthesis, regulation, transport, and iron acquisition. One upregulated gene in the increment rnj mutant is ftsH, coding for a membrane protease (FtsH) involved in cell division, whose overexpression in the wild-type strain also caused cell-width augmentation. Critically, the increment rnj mutant is severely attenuated in virulence in a Caenorhabditis elegans model of infection, while the FtsH-overexpressing and toxin-less strains exhibit full virulence as the wild-type strain. Evidently, RNase J is a key ribonuclease in C. diphtheriae that post-transcriptionally influences the expression of numerous factors vital to corynebacterial cell physiology and virulence. Our findings have significant implications for basic biological processes and mechanisms of corynebacterial pathogenesis.
DA  - 2021
DO  - 10.3390/microorganisms9020389
KW  - Corynebacterium diphtheriae
KW  - actinobacterium
KW  - ribonuclease
KW  - RNase J
KW  - virulence
KW  - Caenorhabditis elegans
KW  - siderophore
KW  - metabolism
KW  - tryptophan
KW  - biosynthesis
LA  - eng
IS  - 2
PY  - 2021
T2  - Microorganisms
TI  - Ribonuclease J-Mediated mRNA Turnover Modulates Cell Shape, Metabolism and Virulence in Corynebacterium diphtheriae
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29527303
Y2  - 2024-11-22T04:26:26
ER  -