RT Journal Article
SR Electronic
T1 No-Go Decay mRNA cleavage in the ribosome exit tunnel produces 5’-OH ends phosphorylated by Trl1
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 465633
DO 10.1101/465633
A1 Albertas Navickas
A1 Sébastien Chamois
A1 Rénette Saint-Fort
A1 Julien Henri
A1 Claire Torchet
A1 Lionel Benard
YR 2019
UL http://biorxiv.org/content/early/2019/12/09/465633.abstract
AB The No-Go Decay (NGD) mRNA surveillance pathway degrades mRNAs containing stacks of stalled ribosomes. Although an endoribonuclease has been proposed to initiate cleavages upstream of the stall sequence, the production of two RNA fragments resulting from a unique cleavage has never been demonstrated. We have used mRNAs expressing a 3’-ribozyme to produce truncated transcripts in vivo to mimic naturally occurring truncated mRNAs known to trigger NGD. This technique allows us to analyse endonucleolytic cleavage events at single-nucleotide resolution starting at the third collided ribosome, which we show to be Hel2-dependent. These cleavages map precisely in the mRNA exit tunnel of the ribosome, 8 nucleotides upstream of the first P-site residue and release 5’-hydroxylated RNA fragments requiring 5’-phosphorylation prior to digestion by the exoribonuclease Xrn1, or alternatively by Dxo1. Finally, we identify the RNA kinase Trl1, alias Rlg1, as an essential player in the degradation of NGD RNAs.