Xrn1 is a deNADding enzyme modulating mitochondrial NAD-capped RNA.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 35173156.
- Also identified by DOI 10.1038/s41467-022-28555-7 and PMC identifier 8850482.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The existence of non-canonical nicotinamide adenine diphosphate (NAD) 5'-end capped RNAs is now well established. Nevertheless, the biological function of this nucleotide metabolite cap remains elusive. Here, we show that the yeast Saccharomyces cerevisiae cytoplasmic 5'-end exoribonuclease Xrn1 is also a NAD cap decapping (deNADding) enzyme that releases intact NAD and subsequently degrades the RNA. The significance of Xrn1 deNADding is evident in a deNADding deficient Xrn1 mutant that predominantly still retains its 5'-monophosphate exonuclease activity. This mutant reveals Xrn1 deNADding is necessary for normal growth on non-fermenting sugar and is involved in modulating mitochondrial NAD-capped RNA levels and may influence intramitochondrial NAD levels. Our findings uncover a contribution of mitochondrial NAD-capped RNAs in overall NAD regulation with the deNADding activity of Xrn1 fulfilling a central role.
Medical subject headings
- Exoribonucleases
- NAD
- RNA Caps
- RNA, Mitochondrial
- Saccharomyces cerevisiae Proteins