Defects in RNA polyadenylation impair both lysogenization by and lytic development of Shiga toxin-converting bacteriophages

Abstract

In Escherichia coli, the major poly(A) polymerase (PAP I) is encoded by the pcnB gene. In this report, a significant impairment of lysogenization by Shiga toxin-converting (Stx) bacteriophages (W24 B , 933W, P22, P27 and P32) is demonstrated in host cells with a mutant pcnB gene. Moreover, lytic development of these phages after both infection and prophage induction was significantly less efficient in the pcnB mutant than in the WT host. The increase in DNA accumulation of the Stx phages was lower under conditions of defective RNA polyadenylation. Although shortly after prophage induction, the levels of mRNAs of most phage-borne early genes were higher in the pcnB mutant, at subsequent phases of the lytic development, a drastically decreased abundance of certain mRNAs, including those derived from the N, O and Q genes, was observed in PAP I-deficient cells. All of these effects observed in the pcnB cells were significantly more strongly pronounced in the Stx phages than in bacteriophage l. Abundance of mRNA derived from the pcnB gene was drastically increased shortly (20 min) after prophage induction by mitomycin C and decreased after the next 20 min, while no such changes were observed in non-lysogenic cells treated with this antibiotic. This prophage induction-dependent transient increase in pcnB transcript may explain the polyadenylation-driven regulation of phage gene expression.

Cinnamon Oil Inhibits Shiga Toxin Type 2 Phage Induction and Shiga Toxin Type 2 Production in Escherichia coli O157:H7

“…PAP I can bind to the 3= terminus of mRNA and further polyadenylates the mRNA, generating substrates readily degraded by PNPase (40). Dysfunction of PAP I has also been reported to inhibit the induction of the Stx-converting phage (19). Consistent with the inhibition of Stx2 prophage induction and reduction of Stx2 phage abundance, cinnamon oil at 0.75ϫ or 1ϫ MIC eliminated both PAP I and PNPase content.…”

“…5A), indicating that additional factors are involved with the inhibitory effect of Stx2 prophage induction. Previous studies showed that dysfunction of PNPase or PAP I, important enzymes in RNA polyadenylation, impaired the lytic development of the Stx2 phage (18,19). Therefore, we evaluated the production of PNPase and PAP I proteins as well as the expression of hfq mRNA, which is an important factor involved in the function of both enzymes.…”

“…Our previous study showed that lytic development of the Stx2-converting phage is positively regulated by polynucleotide phosphorylase (PNPase), an important enzyme in bacterial RNA polyadenylation (18). Dysfunction of another RNA polyadenylation enzyme, poly(A) polymerase (PAP I), has also been reported to downregulate the formation of the Stx-converting phage and subsequent Stx production (19).…”

Effects of some commonly used drinks on induction of Shiga toxin-converting prophage in Escherichia coli

“…To test effects of various commonly used drinks on efficiency of Stx prophage induction in E. coli, MG1655 strain (Jensen 1993) and its derivative carrying a modified (for safety reasons) Stx 933W prophage, 933W Dstx2::cat-gfp (Nowicki et al 2015), were employed. Following drinks were tested at indicated final concentrations in culture medium: Coca-Cola (final concentration 5%), Nestea (final concentration 5%), and vodka _ Zubrówka (final ethanol concentration 1%).…”

The ea22 gene of lambdoid phages: preserved prolysogenic function despite of high sequence diversity

“…Levels of mRNAs were measured by RT-qPCR 15 min after λ phage infection and 35 min after infection with Stx phages (Φ24 B , 933W, P32, P27, P22). These post-infection times were chosen according to our prior knowledge of development of these phages in E. coli bacteria [26,32]. As shown in Fig.…”