Specific splicing defects in S. pombe carrying a degron allele of the Survival of Motor Neuron gene

EMBO J. 2010 Jun 2;29(11):1817-29. doi: 10.1038/emboj.2010.70. Epub 2010 Apr 16.


Spinal muscular atrophy results from deletions or mutations in the survival of motor neuron (SMN1) gene. The SMN protein has an essential role in the biogenesis of spliceosomal snRNPs, but the link between a defect in this process and specific splicing inhibition of pre-mRNAs has not been established. In this study, we report the construction of a temperature-degron (td) allele of the Schizosaccharomyces pombe SMN protein and show that its depletion at 37 degrees C affects splicing and formation of U1, U2, U4 and U5 snRNPs, but not of U6 and U3 ribonucleoproteins. The function of the tdSMN allele in snRNP assembly is already perturbed at 25 degrees C, suggesting a deleterious effect of the tag at this temperature. Using a genome-wide approach, we report that introns react unequally to lower levels of snRNPs in tdSMN cells and that increasing the length of the polypyrimidine tract can improve the splicing efficiency of some, but not all, affected introns. Altogether, our results suggest that the defects observed in tdSMN fission yeast cells mimic splicing deficits observed in SMN-deficient metazoan cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Genes, Fungal*
  • Humans
  • Introns
  • Motor Neurons / metabolism
  • Muscular Atrophy, Spinal / genetics
  • Muscular Atrophy, Spinal / metabolism
  • Mutation
  • RNA Precursors / genetics
  • RNA Precursors / metabolism*
  • RNA Splicing*
  • Ribonucleoproteins / genetics
  • Ribonucleoproteins / metabolism
  • Ribonucleoproteins, Small Nuclear / genetics
  • Ribonucleoproteins, Small Nuclear / metabolism*
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces pombe Proteins / genetics*
  • Spliceosomes / genetics
  • Spliceosomes / metabolism*
  • Survival of Motor Neuron 1 Protein / genetics*
  • snRNP Core Proteins


  • RNA Precursors
  • Ribonucleoproteins
  • Ribonucleoproteins, Small Nuclear
  • Schizosaccharomyces pombe Proteins
  • Survival of Motor Neuron 1 Protein
  • snRNP Core Proteins

Associated data

  • GEO/GSE17010