title: Multiple transcript cleavage precedes polymerase release in termination by RNA polymerase II.
abstract: The requirement of poly(A) signals to elicit transcription termination of RNA polymerase II (pol II) is firmly established. However, little else is known about the actual process of pol II transcription termination. Evidence presented in this paper, based on analysis of nascent transcripts of the human beta- and epsilon-globin genes, demonstrates that pol II transcription termination involves two distinct and temporally separate events. The first event, termed pretermination cleavage (PTC), is mediated by sequence tracts located downstream of the poly(A) site which appear to promote heterogeneous cleavage of the nascent transcript. The second event, in which pol II disengages from the DNA template, requires that polymerase has transcribed both a PTC sequence tract and a functional poly(A) site.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom.
authors.forename: M J
authors.initials: MJ
authors.lastname: Dye
authors.forename: N J
authors.initials: NJ
authors.lastname: Proudfoot
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D002874:Chromosome Mapping; D005914:Globins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D020413:3' Untranslated Regions; D012333:RNA, Messenger; D005914:Globins; D012319:RNA Polymerase II