Splicing inhibition of U2AF65 leads to alternative exon skipping

Proc Natl Acad Sci U S A. 2015 Aug 11;112(32):9926-31. doi: 10.1073/pnas.1500639112. Epub 2015 Jul 27.

Abstract

U2 snRNP auxiliary factor 65 kDa (U2AF(65)) is a general splicing factor that contacts polypyrimidine (Py) tract and promotes prespliceosome assembly. In this report, we show that U2AF(65) stimulates alternative exon skipping in spinal muscular atrophy (SMA)-related survival motor neuron (SMN) pre-mRNA. A stronger 5' splice-site mutation of alternative exon abolishes the stimulatory effects of U2AF(65). U2AF(65) overexpression promotes its own binding only on the weaker, not the stronger, Py tract. We further demonstrate that U2AF(65) inhibits splicing of flanking introns of alternative exon in both three-exon and two-exon contexts. Similar U2AF(65) effects were observed in Fas (Apo-1/CD95) pre-mRNA. Strikingly, we demonstrate that U2AF(65) even inhibits general splicing of adenovirus major late (Ad ML) or β-globin pre-mRNA. Thus, we conclude that U2AF(65) possesses a splicing Inhibitory function that leads to alternative exon skipping.

Keywords: SMN; U2AF65; exon exclusion; pre-mRNA splicing; splicing inhibition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing / genetics*
  • Base Sequence
  • DNA-Binding Proteins / genetics
  • Exons / genetics*
  • HEK293 Cells
  • Humans
  • Introns / genetics
  • Molecular Sequence Data
  • Nuclear Proteins / chemistry
  • Nuclear Proteins / genetics*
  • Protein Binding
  • Protein Structure, Tertiary
  • RNA Precursors / genetics
  • RNA Precursors / metabolism
  • RNA Splice Sites / genetics
  • Ribonucleoproteins / chemistry
  • Ribonucleoproteins / genetics*
  • SMN Complex Proteins / genetics
  • Splicing Factor U2AF
  • Structure-Activity Relationship
  • Transcription Factors / genetics
  • Viral Proteins / genetics
  • beta-Globins / genetics
  • tau Proteins / genetics

Substances

  • DNA-Binding Proteins
  • MLTF protein, adenovirus
  • Nuclear Proteins
  • RNA Precursors
  • RNA Splice Sites
  • Ribonucleoproteins
  • SMN Complex Proteins
  • Splicing Factor U2AF
  • Transcription Factors
  • U2AF2 protein, human
  • Viral Proteins
  • beta-Globins
  • tau Proteins