Prp43p is a DEAH-box spliceosome disassembly factor essential for ribosome biogenesis

Mol Cell Biol. 2006 Jan;26(2):523-34. doi: 10.1128/MCB.26.2.523-534.2006.

Abstract

The known function of the DEXH/D-box protein Prp43p is the removal of the U2, U5, and U6 snRNPs from the postsplicing lariat-intron ribonucleoprotein complex. We demonstrate that affinity-purified Prp43p-associated material includes the expected spliceosomal components; however, we also identify several preribosomal complexes that are specifically purified with Prp43p. Conditional prp43 mutant alleles confer a 35S pre-rRNA processing defect, with subsequent depletion of 27S and 20S precursors. Upon a shift to a nonpermissive temperature, both large and small-ribosomal-subunit proteins accumulate in the nucleolus of prp43 mutants. Pulse-chase analysis demonstrates delayed kinetics of 35S, 27S, and 20S pre-rRNA processing with turnover of these intermediates. Microarray analysis of pre-mRNA splicing defects in prp43 mutants shows a very mild effect, similar to that of nonessential pre-mRNA splicing factors. Prp43p is the first DEXH/D-box protein shown to function in both RNA polymerase I and polymerase II transcript metabolism. Its essential function is in its newly characterized role in ribosome biogenesis of both ribosomal subunits, positioning Prp43p to regulate both pre-mRNA splicing and ribosome biogenesis.

Publication types

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

MeSH terms

  • Cell Nucleolus / genetics
  • Cell Nucleolus / physiology
  • Computational Biology
  • DEAD-box RNA Helicases
  • Introns
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • RNA Helicases / genetics
  • RNA Helicases / physiology*
  • RNA Polymerase I / genetics
  • RNA Polymerase I / physiology
  • RNA Polymerase II / genetics
  • RNA Polymerase II / physiology
  • RNA Precursors / genetics*
  • RNA Precursors / physiology
  • RNA Splicing / genetics*
  • RNA Splicing / physiology
  • RNA, Small Nuclear / genetics
  • RNA, Small Nuclear / physiology
  • Ribosomes / genetics*
  • Ribosomes / physiology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / physiology*

Substances

  • RNA Precursors
  • RNA, Small Nuclear
  • Saccharomyces cerevisiae Proteins
  • RNA Polymerase II
  • RNA Polymerase I
  • PRP43 protein, S cerevisiae
  • DEAD-box RNA Helicases
  • RNA Helicases