title: Bacteriophage T4 polynucleotide kinase triggers degradation of mRNAs.
abstract: The bacteriophage T4-encoded RegB endoribonuclease is produced during the early stage of phage development and targets mostly (but not exclusively) the Shine-Dalgarno sequences of early genes. In this work, we show that the degradation of RegB-cleaved mRNAs depends on a functional T4 polynucleotide kinase/phosphatase (PNK). The 5'-OH produced by RegB cleavage is phosphorylated by the kinase activity of PNK. This modification allows host RNases G and E, with activity that is strongly stimulated by 5'-monophosphate termini, to attack mRNAs from the 5'-end, causing their destabilization. The PNK-dependent pathway of degradation becomes effective 5 min postinfection, consistent with our finding that several minutes are required for PNK to accumulate after infection. Our work emphasizes the importance of the nature of the 5' terminus for mRNA stability and depicts a pathway of mRNA degradation with 5'- to 3'-polarity in cells devoid of 5'-3' exonucleases. It also ascribes a role for T4 PNK during normal phage development.
authors.affiliation: Institut de Biologie Physico-chimique, Unité Propre de Recherche 9073, Centre National de la Recherche Scientifique affiliated with Université Paris Diderot, 75005 Paris, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Durand
authors.forename: Graziella
authors.initials: G
authors.lastname: Richard
authors.forename: François
authors.initials: F
authors.lastname: Bontems
authors.forename: Marc
authors.initials: M
authors.lastname: Uzan
mesh_terms: D017122:Bacteriophage T4 / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001483:Base Sequence; D004722:Endoribonucleases / Q000037:antagonists & inhibitors / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005814:Genes, Viral; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D011116:Polynucleotide 5'-Hydroxyl-Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins; D011116:Polynucleotide 5'-Hydroxyl-Kinase; D004722:Endoribonucleases; C081905:rng protein, E coli; C407103:T4 RegB endoribonuclease; C022537:ribonuclease E