In eukaryotes, mRNA 3′-polyadenylation triggers poly(A) binding protein (PABP) recruitment and stabilization. In a stark contrast, polyadenylation marks mRNAs for degradation in bacteria. To study this difference, we trans-express the mammalian nuclear PABPN1 chromosomally and extra-chromosomally in Escherichia coli. Expression of PABPN1 but not the mutant PABPN1 stabilizes polyadenylated mRNAs and improves their half-lives. In the presence of PABPN1, 3′-exonuclease PNPase is not detected on PA-tailed mRNAs compromising the degradation. We show that PABPN1 trans-expression phenocopies pcnB (that encodes poly(A) polymerase, PAPI) mutation and regulates plasmid copy number. Genome-wide RNA-seq analysis shows a general up-regulation of polyadenylated mRNAs on PABPN1 expression, the largest subset of which are those involved in general stress response. However, major global stress regulators are unaffected on PABPN1 expression. Concomitantly, PABPN1 expression or pcnB mutation imparts cellular tolerance to multiple stresses. This study establishes mRNA 3′-polyadenylation as a general stress response mechanism in E. coli.

在真核生物中，mRNA 3'-聚腺苷酸化触发 poly(A) 结合蛋白 (PABP) 募集和稳定化。形成鲜明对比的是，聚腺苷酸化标记 mRNA 在细菌中降解。为了研究这种差异，我们在大肠杆菌中在染色体和染色体外反式表达哺乳动物核 PABPN1 。PABPN1 的表达而不是突变体 PABPN1 的表达稳定了聚腺苷酸化的 mRNA 并延长了它们的半衰期。在存在 PABPN1 的情况下，在影响降解的 PA 尾 mRNA 上未检测到 3'-外切核酸酶 PNPase。我们表明 PABPN1 反式表达表型pcnB（编码poly（A）聚合酶，PAPI）突变并调节质粒拷贝数。全基因组 RNA-seq 分析显示多腺苷酸化 mRNA 对 PABPN1 表达的普遍上调，其中最大的子集是参与一般应激反应的那些。然而，主要的全球压力调节因子对 PABPN1 表达不受影响。同时，PABPN1 表达或pcnB突变赋予细胞对多种压力的耐受性。本研究建立的mRNA 3'多聚腺苷酸化作为一般的应激反应机制ê。大肠杆菌。