The transcription activation domains of v-Myc and VP16 interact with common factors required for cellular transformation and proliferation

Cell Growth Differ. 1994 Jun;5(6):563-73.


The amino terminus of the avian myelocytomatosis virus MC29 v-Myc oncoprotein contains sequences that are essential for cellular transformation (S. Farina, et al. J. Virol., 66: 2698-2708, 1992; S. Min and E. J. Taparowsky. Oncogene, 7:1531-1540, 1992) and for the ability to activate gene transcription (S. Min and E. J. Taparowsky. Oncogene, 7:1531-1540, 1992). To investigate the molecular interactions that mediate these v-Myc-associated activities, we performed competition assays in which various regions of the v-Myc amino terminal transcription activation domain (TAD) were examined for their ability to inhibit transcription activation by v-Myc, VP16, and the myogenic regulatory factor MyoD. Overexpression of these transcriptional activators also was used to investigate whether Myc-interacting proteins were required for cellular transformation and cell proliferation events. Our results demonstrate that at least two distinct cellular activities interact with the v-Myc TAD and that it is the synergism between these activities that is required for v-Myc to function fully as a transcriptional activator. In addition, v-Myc activators squelch VP16- and MyoD-dependent transcription activation, suggesting that the v-Myc TAD interacts with a component of the general transcription machinery. In support of this observation, we found that overexpression of the v-Myc TAD inhibits ras-mediated cellular transformation as well as cell proliferation, underscoring the critical role these amino terminal Myc-interacting factors play in regulating the physiology of both normal and transformed cells.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Binding, Competitive
  • Cell Division
  • Cell Line, Transformed
  • Cell Transformation, Neoplastic
  • DNA Probes
  • Escherichia coli
  • Gene Expression Regulation
  • Genes, myc
  • Herpes Simplex Virus Protein Vmw65 / chemistry
  • Herpes Simplex Virus Protein Vmw65 / genetics*
  • Molecular Sequence Data
  • MyoD Protein / chemistry
  • MyoD Protein / physiology*
  • Oncogene Protein p21(ras) / genetics
  • Oncogene Protein p55(v-myc) / biosynthesis
  • Oncogene Protein p55(v-myc) / chemistry
  • Oncogene Protein p55(v-myc) / physiology*
  • Oncogene Proteins, Viral / chemistry
  • Oncogene Proteins, Viral / genetics
  • Oncogene Proteins, Viral / physiology*
  • Simplexvirus / chemistry
  • Simplexvirus / genetics
  • Transcription Factors / biosynthesis*


  • DNA Probes
  • Herpes Simplex Virus Protein Vmw65
  • MyoD Protein
  • Oncogene Protein p55(v-myc)
  • Oncogene Proteins, Viral
  • Transcription Factors
  • Oncogene Protein p21(ras)