title: Polyadenylation and degradation of incomplete RNA polymerase I transcripts in mammalian cells.
abstract: Most transcripts in growing cells are ribosomal RNA precursors (pre-rRNA). Here, we show that in mammals, aberrant pre-rRNA transcripts generated by RNA polymerase I (Pol I) are polyadenylated and accumulate markedly after treatment with low concentrations of actinomycin D (ActD), which blocks the synthesis of full-length rRNA. The poly(A) polymerase-associated domain-containing protein 5 is required for polyadenylation, whereas the exosome is partly responsible for the degradation of the short aberrant transcripts. Thus, polyadenylation functions in the quality control of Pol I transcription in metazoan cells. The impact of excessive aberrant RNAs on the degradation machinery is an unrecognized mechanism that might contribute to biological properties of ActD.
authors.affiliation: Department of Cell Biology, University of Medicine and Dentistry of New Jersey, 2 Medical Center Drive, Stratford, New Jersey 08084, USA.
authors.forename: Natalia
authors.initials: N
authors.lastname: Shcherbik
authors.forename: Minshi
authors.initials: M
authors.lastname: Wang
authors.forename: Yevgeniya R
authors.initials: YR
authors.lastname: Lapik
authors.forename: Leena
authors.initials: L
authors.lastname: Srivastava
authors.forename: Dimitri G
authors.initials: DG
authors.lastname: Pestov
mesh_terms: D000818:Animals; D018389:Codon, Nonsense / Q000235:genetics / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D005057:Eukaryotic Cells / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008322:Mammals / Q000235:genetics / Q000378:metabolism; D051379:Mice; D041681:NIH 3T3 Cells; D026723:Polyadenylation / Q000502:physiology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012318:RNA Polymerase I / Q000235:genetics* / Q000378:metabolism; D020871:RNA Stability / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D014162:Transfection
chemical_list: D018389:Codon, Nonsense; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D003609:Dactinomycin; D012318:RNA Polymerase I