Extensive coupling of alternative splicing of pre-mRNAs of serine/arginine (SR) genes with nonsense-mediated decay

New Phytol. 2010 Jan;185(1):83-9. doi: 10.1111/j.1469-8137.2009.03065.x. Epub 2009 Oct 23.

Abstract

In Arabidopsis, pre-mRNAs encoding serine/arginine (SR) proteins, key regulators of constitutive and alternative splicing, are extensively alternatively spliced. In seedlings, 13 SR genes are alternatively spliced to generate 75 transcripts, of which 53 contain a premature termination codon (PTC). However, it is not known if any of the PTC-containing splice variants are the targets of nonsense-mediated decay (NMD) and if there is any link between NMD and the abundance of functional transcripts. Here, we analyzed the abundances of all splice variants for each alternatively spliced gene in an Arabidopsis mutant that lacks UPF3, one of the core components of NMD machinery, to determine if the PTC-containing transcripts are degraded by NMD. Our results show that about half of the 53 splice variants with a PTC are the targets of degradation by NMD. The accumulation of PTC-containing transcripts resulted in concomitant reduction in the amount of functional transcript. These results show widespread coupling of alternative splicing with NMD in the SR gene family, suggesting a strong link between unproductive splicing and the abundance of functional transcripts.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alternative Splicing*
  • Amino Acids / genetics
  • Arabidopsis / genetics*
  • Arabidopsis Proteins / genetics
  • Arginine / genetics*
  • Codon, Nonsense / metabolism*
  • Gene Expression Regulation, Plant
  • Genes, Plant
  • Mutation
  • RNA Precursors / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Serine / genetics*

Substances

  • Amino Acids
  • Arabidopsis Proteins
  • Codon, Nonsense
  • RNA Precursors
  • UPF3 protein, Arabidopsis
  • Serine
  • Arginine