Pluto Bioinformatics

GSE57433: Human Nonsense-Mediated RNA Decay Initiates Widely by Endonucleolysis and Targets snoRNA Host Genes

Bulk RNA sequencing

Eukaryotic RNAs with premature termination codons (PTCs) are eliminated by nonsense-mediated decay (NMD). While human nonsense RNA degradation can be initiated either by an endonucleolytic cleavage event near the PTC or through decapping, the individual contribution of these activities on endogenous substrates has remained unresolved. Here we unambiguously establish that SMG6-catalyzed endonucleolysis is the primary initiating step in human nonsense RNA decay. We also show that both protein-coding and non-coding genes hosting snoRNAs in their introns produce considerable amounts of NMD-sensitive splice variants, suggesting that these RNAs are merely by-products of a primary snoRNA production process. Finally, genes encoding multiple snoRNAs generally yield elevated numbers of alternative transcript isoforms, enabling the differential expression of individual snoRNAs. These findings demonstrate a hitherto unappreciated potential for decoupling of the individual expression levels of functional exon- and intron-encoded species from such composite genes. SOURCE: Yun Chen (yuc@binf.ku.dk) - Sandelin Lab Univeristy of Copenhagen