A dominant-negative mutant of Max that inhibits sequence-specific DNA binding by Myc proteins

Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2739-43. doi: 10.1073/pnas.90.7.2739.

Abstract

Myc proteins are basic helix-loop-helix/leucine-zipper proteins that bind to specific DNA sequences. In vivo, Myc proteins have been found associated with Max, another basic helix-loop-helix/leucine-zipper protein. However, it is not known to what extent the dimerization of Myc with Max is required for the manifestation of the Myc-induced phenotype. To investigate this, we constructed a dominant-negative mutant of Max, named dMax, that inhibits sequence-specific DNA binding of Myc proteins. Using a rat neuroblastoma model system, we show that dMax reverts N-Myc-induced changes in cellular gene expression. A control mutant of dMax that contains a proline residue in the leucine-zipper region was unable to bind to N-Myc and did not revert the N-Myc-induced changes in cellular gene expression. These data support the hypothesis that N-Myc affects neuroblastoma gene expression through the formation of a DNA-binding heterodimeric complex with Max in vivo.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic-Leucine Zipper Transcription Factors
  • Cloning, Molecular
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Genes, Dominant
  • Genes, myc*
  • Molecular Sequence Data
  • Mutagenesis
  • Neuroblastoma
  • Oligodeoxyribonucleotides
  • Polymerase Chain Reaction / methods
  • Protein Biosynthesis
  • Proto-Oncogene Proteins c-myc / biosynthesis
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • Rats
  • Sequence Deletion
  • Transcription Factors*
  • Transcription, Genetic
  • Transfection
  • Tumor Cells, Cultured

Substances

  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic-Leucine Zipper Transcription Factors
  • DNA-Binding Proteins
  • Max protein, rat
  • Myc associated factor X
  • Oligodeoxyribonucleotides
  • Proto-Oncogene Proteins c-myc
  • Transcription Factors