Ceg1 depletion reveals mechanisms governing degradation of non-capped RNAs

Onofrio Zanin, Daniel Hebenstreit, Pawel Grzechnik
2022 · doi:10.1101/2022.09.24.509330
preprint OA: gold CC-BY-4.0
📄 Open PDF View at publisher

Abstract

ABSTRACT Most functional eukaryotic mRNAs contain a 7-methylguanosine (m7G) cap which serves as a platform that recruits proteins to support essential biological functions such as mRNA processing, nuclear export and translation. Although capping is accomplished during the first steps of transcription the fate and turnover of uncapped transcripts have not been studied extensively. Here, we employed fast nuclear depletion of the capping enzymes in Saccharomyces cerevisiae to uncover the turnover of the transcripts that failed to be capped. We show that the levels of non-capped mRNAs are determined principally by the abundance of their synthesis. Nuclear depletion of the capping enzymes increases the levels of lowly expressed mRNAs and decreases mRNAs that are highly transcribed altogether mimicking the effects observed in cells lacking the predominantly cytoplasmic 5’-3’ exonuclease Xrn1. The nuclear 5’-3’ exonuclease Rat1 is not involved in the degradation of cap-defective transcripts and the lack of the capping does not affect the distribution of RNA Polymerase II on the chromatin. Our data indicate that the mRNAs that failed to be capped are not directed to a specific quality-control pathway and that the 5’ cap role is associated with the Xrn1-dependent buffering of the cellular mRNA levels, along with protecting from 5’-3’ degradation.

My notes (saved in your browser only)

Citation neighborhood (no data yet)

We don't have any in-corpus citations linked to this paper yet. The paper's references may be in our DB but unresolved to ``paper_id`` (resolution happens at ingest when the cited DOI matches a row we already have). Run the cross-source citation reconcile pass to retry.

References (47)

Source provenance

crossref
last seen: 2026-05-28T01:00:27.250508+00:00
europepmc
last seen: 2026-05-19T01:45:01.086888+00:00
unpaywall
last seen: 2026-05-21T02:00:01.467718+00:00
License: CC-BY-4.0