Fail-safe transcription termination: Because one is never enough.
Termination of RNA polymerase II (RNAPII) transcription is a fundamental step of gene expression that involves the release of the nascent transcript and dissociation of RNAPII from the DNA template. As transcription termination is intimately linked to RNA 3' end processing, termination pathways have a key decisive influence on the fate of the transcribed RNA. Quite remarkably, when reaching the 3' end of genes, a substantial fraction of RNAPII fail to terminate transcription, requiring the contribution of alternative or "fail-safe" mechanisms of termination to release the polymerase. This point of view covers redundant mechanisms of transcription termination and how they relate to conventional termination models. In particular, we expand on recent findings that propose a reverse torpedo model of termination, in which the 3'5' exonucleolytic activity of the RNA exosome targets transcription events associated with paused and backtracked RNAPII.
a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec.
Jean-François
JF
Lemay
a Department of Biochemistry ; Faculté de Médecine et des Sciences de la Santé; Université de Sherbrooke; Pavillon de Recherche Appliquée sur le Cancer (PRAC) ; Sherbrooke, Quebec.
François
F
Bachand
D063326:Exosome Multienzyme Ribonuclease Complex / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D012320:RNA Polymerase III / Q000378:metabolism; D061806:Transcription Termination, Genetic; D015003:Yeasts / Q000235:genetics / Q000378:metabolism
D012313:RNA; D012319:RNA Polymerase II; D012320:RNA Polymerase III; D063326:Exosome Multienzyme Ribonuclease Complex
3′ end processing; Nrd1; RNA exosome; RNA polymerase II; Rat1; TFIIS; backtracking; fail-safe termination; transcription termination