The Caenorhabditis elegans ortholog of TRAP240, CeTRAP240/let-19, selectively modulates gene expression and is essential for embryogenesis

J Biol Chem. 2004 Jul 9;279(28):29270-7. doi: 10.1074/jbc.M401242200. Epub 2004 Apr 8.


Mediator complexes are large multiprotein assemblies that function in the regulation of eukaryotic gene transcription. In yeast, certain mediator subunits appear to comprise a subcomplex that acts in the regulation of a specific subset of genes. We investigated in a metazoan, Caenorhabditis elegans, the roles and interactions of two of those subunits, CeTRAP240/let-19 and CeTRAP230/dpy-22. We found that CeTRAP240/let-19 contains four domains that are conserved in the human TRAP240 protein and that one of those domains displays intrinsic transcriptional repression activity. Using RNA interference, we found that reduced expression of CeTRAP240/let-19 displayed a high penetrance of embryonic lethality in F1 progeny; animals that escaped embryonic arrest showed mutant phenotypes such as burst vulva and molting defects. CeTRAP240/let-19 appeared to affect specific genes, as CeTRAP240/let-19(RNAi) led to selectively reduced expression of a subset of reporter genes examined. Genetic experiments supported the view that CeTRAP240/let-19 and CeTRAP230/dpy-22, like their Drosophila and yeast counterparts, can operate on common pathways. Thus, a male tail phenotype caused by the pal-1(e2091) mutation was suppressed not only by CeTRAP230/dpy-22 mutants, as reported previously, but also by reduced expression of CeTRAP240/let-19. Additionally, CeTRAP240/let-19(RNAi) in a CeTRAP230/dpy-22 mutant background produced a strong synthetic lethal phenotype. Overall, our results establish specific roles of CeTRAP240/let-19 in C. elegans embryonic development and a functional interaction between CeTRAP240/let-19 and CeTRAP230/dpy-22. Interestingly, whereas this interaction has been conserved from yeast to mammals, the subcomplex modulates metazoan-specific genetic pathways, likely in addition to those also controlled in yeast.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans / anatomy & histology
  • Caenorhabditis elegans / embryology*
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism*
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism*
  • Gene Expression Regulation*
  • Genes, Reporter
  • Humans
  • Macromolecular Substances
  • Male
  • Mediator Complex
  • Molecular Sequence Data
  • Phenotype
  • Promoter Regions, Genetic
  • Protein Subunits / genetics
  • Protein Subunits / metabolism*
  • RNA Interference
  • RNA Polymerase II / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Caenorhabditis elegans Proteins
  • MED13 protein, human
  • Macromolecular Substances
  • Mediator Complex
  • Protein Subunits
  • Recombinant Fusion Proteins
  • Transcription Factors
  • let-19 protein, C elegans
  • RNA Polymerase II