Proteomic analysis identifies a new complex required for nuclear pre-mRNA retention and splicing

EMBO J. 2004 Dec 8;23(24):4847-56. doi: 10.1038/sj.emboj.7600482. Epub 2004 Nov 25.


Using the proteomic tandem affinity purification (TAP) method, we have purified the Saccharomyces cerevisie U2 snRNP-associated splicing factors SF3a and SF3b. While SF3a purification revealed only the expected subunits Prp9p, Prp11p and Prp21p, yeast SF3b was found to contain only six subunits, including previously known components (Rse1p, Hsh155p, Cus1p, Hsh49p), the recently identified Rds3p factor and a new small essential protein (Ysf3p) encoded by an unpredicted split ORF in the yeast genome. Surprisingly, Snu17p, the proposed yeast orthologue of the seventh human SF3b subunit, p14, was not found in the yeast complex. TAP purification revealed that Snu17p, together with Bud13p and a newly identified factor, Pml1p/Ylr016c, form a novel trimeric complex. Subunits of this complex were not essential for viability. However, they are required for efficient splicing in vitro and in vivo. Furthermore, inactivation of this complex causes pre-mRNA leakage from the nucleus. The corresponding complex was named pre-mRNA REtention and Splicing (RES). The presence of RES subunit homologues in numerous eukaryotes suggests that its function is evolutionarily conserved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Cell Nucleus / metabolism*
  • Humans
  • Macromolecular Substances
  • Molecular Sequence Data
  • Phylogeny
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Proteome / analysis*
  • RNA Precursors / metabolism*
  • RNA Splicing*
  • Ribonucleoprotein, U2 Small Nuclear / classification
  • Ribonucleoprotein, U2 Small Nuclear / genetics
  • Ribonucleoprotein, U2 Small Nuclear / isolation & purification
  • Ribonucleoprotein, U2 Small Nuclear / metabolism
  • Saccharomyces cerevisiae Proteins / classification
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / isolation & purification
  • Saccharomyces cerevisiae Proteins / metabolism
  • Sequence Alignment


  • Macromolecular Substances
  • Protein Subunits
  • Proteome
  • RNA Precursors
  • Ribonucleoprotein, U2 Small Nuclear
  • Saccharomyces cerevisiae Proteins