Nowicki Dariusz, Bloch Sylwia, Nejman-Faleńczyk Bożena, Szalewska-Pałasz Agnieszka, Węgrzyn Alicja, Węgrzyn Grzegorz
1Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
2Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdańsk, Poland.
J Gen Virol. 2015 Jul;96(Pt 7):1957-68. doi: 10.1099/vir.0.000102. Epub 2015 Feb 23.
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 (Φ24B, 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 λ. 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.
在大肠杆菌中，主要的聚腺苷酸聚合酶（PAP I）由pcnB基因编码。在本报告中，发现在具有pcnB基因突变的宿主细胞中，志贺毒素转换（Stx）噬菌体（Φ24B、933W、P22、P27和P32）的溶原化受到显著损害。此外，在pcnB突变体中，这些噬菌体在感染和原噬菌体诱导后的裂解发育效率明显低于野生型宿主。在RNA聚腺苷酸化缺陷的条件下，Stx噬菌体的DNA积累增加较低。尽管在原噬菌体诱导后不久，pcnB突变体中大多数噬菌体携带的早期基因的mRNA水平较高，但在裂解发育的后续阶段，在缺乏PAP I的细胞中观察到某些mRNA的丰度急剧下降，包括那些源自N、O和Q基因的mRNA。在pcnB细胞中观察到的所有这些效应在Stx噬菌体中比在噬菌体λ中明显更显著。在丝裂霉素C诱导原噬菌体后不久（20分钟），源自pcnB基因的mRNA丰度急剧增加，在接下来的20分钟后下降，而在用这种抗生素处理的非溶原性细胞中未观察到这种变化。这种原噬菌体诱导依赖性的pcnB转录本瞬时增加可能解释了聚腺苷酸化驱动的噬菌体基因表达调控。
