A dominant-negative mutant of Max that inhibits sequence-specific DNA binding by Myc proteins.
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.
Billaud
M
M
Division of Molecular Genetics, Massachusetts General Hospital, Charlestown.
Isselbacher
K J
KJ
Bernards
R
R
D000818:Animals; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D005799:Genes, Dominant; D016259:Genes, myc; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009447:Neuroblastoma; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D014176:Protein Biosynthesis; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017384:Sequence Deletion; D014157:Transcription Factors; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C499329:Max protein, rat; C067850:Myc associated factor X; D009838:Oligodeoxyribonucleotides; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors