An amino-terminal domain of Mxi1 mediates anti-Myc oncogenic activity and interacts with a homolog of the yeast transcriptional repressor SIN3

Cell. 1995 Mar 10;80(5):777-86. doi: 10.1016/0092-8674(95)90356-9.


Documented interactions among members of the Myc superfamily support a yin-yang model for the regulation of Myc-responsive genes in which transactivation-competent Myc-Max heterodimers are opposed by repressive Mxi1-Max or Mad-Max complexes. Analysis of mouse mxi1 has led to the identification of two mxi1 transcript forms possessing open reading frames that differ in their capacity to encode a short amino-terminal alpha-helical domain. The presence of this segment dramatically augments the suppressive potential of Mxi1 and allows for association with a mammalian protein that is structurally homologous to the yeast transcriptional repressor SIN3. These findings provide a mechanistic basis for the antagonistic actions of Mxi1 on Myc activity that appears to be mediated in part through the recruitment of a putative transcriptional repressor.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Basic Helix-Loop-Helix Transcription Factors
  • Cell Line, Transformed
  • Cloning, Molecular
  • Conserved Sequence
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Histone Deacetylases
  • Mice
  • Molecular Sequence Data
  • Protein Structure, Secondary
  • Proto-Oncogene Proteins c-myc / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-myc / genetics
  • RNA, Messenger / genetics
  • Recombinant Fusion Proteins / biosynthesis
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae Proteins*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Transcription Factors*
  • Transcription, Genetic / genetics*
  • Tumor Suppressor Proteins


  • Basic Helix-Loop-Helix Transcription Factors
  • DNA-Binding Proteins
  • Fungal Proteins
  • MXI1 protein, human
  • Mxi1 protein, mouse
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • SIN3 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • Histone Deacetylases

Associated data

  • GENBANK/L38821
  • GENBANK/L38822
  • GENBANK/U32512
  • GENBANK/U32513
  • GENBANK/U32514
  • GENBANK/U32515