There are multiple RNA degradation mechanisms in eukaryotes, key among these is mRNA decapping, which requires the Dcp1‐Dcp2 complex. Decapping is involved in various processes including nonsense‐mediated decay (NMD), a process by which aberrant transcripts with a premature termination codon are targeted for translational repression and rapid decay. NMD is ubiquitous throughout eukaryotes and the key factors involved are highly conserved, although many differences have evolved. We investigated the role of Aspergillus nidulans decapping factors in NMD and found that they are not required, unlike Saccharomyces cerevisiae. Intriguingly, we also observed that the disruption of one of the decapping factors, Dcp1, leads to an aberrant ribosome profile. Importantly this was not shared by mutations disrupting Dcp2, the catalytic component of the decapping complex. The aberrant profile is associated with the accumulation of a high proportion of 25S rRNA degradation intermediates. We identified the location of three rRNA cleavage sites and show that a mutation targeted to disrupt the catalytic domain of Dcp2 partially suppresses the aberrant profile of Δdcp1 strains. This suggests that in the absence of Dcp1, cleaved ribosomal components accumulate and Dcp2 may be directly involved in mediating these cleavage events. We discuss the implications of this.
Bibliographical noteThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.© 2023 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.
FunderThis work was supported by grants from the BBSRC (BB/H020365) to MXC to support IYM. the Ministerio de Economía Y Competitividad Grant (MINECO; PID2021‐122705OB‐I00 and CTQ201782222‐R) to Paola Fucini and S.R.C. Gene analysis and orthologue identification used the FungiDB database.
© 2023 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd
- Aspergillus nidulans
- nonsense-dediated decay
- polysomal fractionation
ASJC Scopus subject areas
- Molecular Biology