TOR Facilitates the Targeting of the 19S Proteasome Subcomplex To Enhance Transcription Complex Assembly at the Promoters of the Ribosomal Protein Genes

Mol Cell Biol. 2018 Jun 28;38(14):e00469-17. doi: 10.1128/MCB.00469-17. Print 2018 Jul 15.


TOR (target of rapamycin) has been previously implicated in transcriptional stimulation of the ribosomal protein (RP) genes via enhanced recruitment of NuA4 (nucleosome acetyltransferase of H4) to the promoters. However, it is not clearly understood how TOR enhances NuA4 recruitment to the promoters of the RP genes. Here we show that TOR facilitates the recruitment of the 19S proteasome subcomplex to the activator to enhance the targeting of NuA4 to the promoters of the RP genes. NuA4, in turn, promotes the recruitment of TFIID (transcription factor IID, composed of TATA box-binding protein [TBP] and a set of TBP-associated factors [TAFs]) and RNA polymerase II to the promoters of the RP genes to enhance transcriptional initiation. Therefore, our results demonstrate that TOR facilitates the recruitment of the 19S proteasome subcomplex to the promoters of the RP genes to promote the targeting of NuA4 for enhanced preinitiation complex (PIC) formation and consequently transcriptional initiation, hence illuminating TOR regulation of RP gene activation. Further, our results reveal that TOR differentially regulates PIC formation (and hence transcription) at the non-RP genes, thus demonstrating a complex regulation of gene activation by TOR.

Keywords: 19S proteasome subcomplex; NuA4; RNA polymerase II; TBP; TOR; transcription.

Publication types

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

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism
  • Gene Expression Regulation, Fungal
  • Genes, Fungal
  • Histone Acetyltransferases / genetics
  • Histone Acetyltransferases / metabolism
  • Models, Biological
  • Mutation
  • Promoter Regions, Genetic
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism*
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism*
  • Ribosomal Proteins / genetics*
  • Ribosomal Proteins / metabolism*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Transcription Factor TFIID / genetics
  • Transcription Factor TFIID / metabolism
  • Transcriptional Activation


  • Ribosomal Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factor TFIID
  • Histone Acetyltransferases
  • NuA4 protein, S cerevisiae
  • Protein Serine-Threonine Kinases
  • target of rapamycin protein, S cerevisiae
  • Proteasome Endopeptidase Complex
  • Adenosine Triphosphatases
  • RPT4 protein, S cerevisiae