Aberrant mRNA Transcripts and the Nonsense-Mediated Decay Proteins UPF2 and UPF3 Are Enriched in the Arabidopsis Nucleolus

Kim, S. H., Koroleva, O., Lewandowska, D., Pendle, A., Clark, G., Simpson, C., Shaw, P. and Brown, J. (2009) Aberrant mRNA Transcripts and the Nonsense-Mediated Decay Proteins UPF2 and UPF3 Are Enriched in the Arabidopsis Nucleolus. The Plant Cell , 21 (7). pp. 2045-2057. ISSN 1040-4651 doi: 10.1105/tpc.109.067736

Abstract/Summary

The eukaryotic nucleolus is multifunctional and involved in the metabolism and assembly of many different RNAs and ribonucleoprotein particles as well as in cellular functions, such as cell division and transcriptional silencing in plants. We previously showed that Arabidopsis thaliana exon junction complex proteins associate with the nucleolus, suggesting a role for the nucleolus in mRNA production. Here, we report that the plant nucleolus contains mRNAs, including fully spliced, aberrantly spliced, and single exon gene transcripts. Aberrant mRNAs are much more abundant in nucleolar fractions, while fully spliced products are more abundant in nucleoplasmic fractions. The majority of the aberrant transcripts contain premature termination codons and have characteristics of nonsense-mediated decay (NMD) substrates. A direct link between NMD and the nucleolus is shown by increased levels of the same aberrant transcripts in both the nucleolus and in Up-frameshift (upf) mutants impaired in NMD. In addition, the NMD factors UPF3 and UPF2 localize to the nucleolus, suggesting that the Arabidopsis nucleolus is therefore involved in identifying aberrant mRNAs and NMD.

Additional Information	Full text is available open access via publisher's website (DOI)
Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/4479
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Biological Sciences
Uncontrolled Keywords	exon-junction complex; cajal bodies; termination codons; processing center; mammalian-cells; quality-control; nuclear-bodies; higher-plants; p-bodies; translation
Additional Information	Full text is available open access via publisher's website (DOI)
Publisher	American Society of Plant Biologists
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