Mxi1, a protein that specifically interacts with Max to bind Myc-Max recognition sites

Cell. 1993 Jan 29;72(2):223-32. doi: 10.1016/0092-8674(93)90662-a.

Abstract

We used the interaction trap to isolate a novel human protein that specifically interacts with Max. This protein, Mxi1 (for Max interactor 1), contains a bHLH-Zip motif that is similar to that found in Myc family proteins. Mxi1 interacts specifically with Max to form heterodimers that efficiently bind to the Myc-Max consensus recognition site. When bound to DNA by a LexA moiety in yeast, Mxi1 does not stimulate transcription. mxi1 mRNA is expressed in many tissues, and its expression is elevated in U-937 myeloid leukemia cells that have been stimulated to differentiate. These facts are consistent with a model in which Mxi1-Max heterodimers indirectly inhibit Myc function in two ways: first, by sequestering Max, thus preventing the formation of Myc-Max heterodimers, and second, by competing with Myc-Max heterodimers for binding to target sites.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic Helix-Loop-Helix Transcription Factors
  • Basic-Leucine Zipper Transcription Factors
  • Binding Sites
  • Cell Differentiation / physiology
  • Cloning, Molecular
  • DNA, Neoplasm / genetics
  • DNA, Neoplasm / isolation & purification
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism*
  • Escherichia coli / genetics
  • Gene Library
  • Genes, myc
  • HeLa Cells
  • Humans
  • Leucine Zippers / genetics
  • Leucine Zippers / physiology*
  • Macromolecular Substances
  • Molecular Sequence Data
  • Oligodeoxyribonucleotides
  • Open Reading Frames
  • Plasmids
  • Protein Structure, Secondary
  • Proto-Oncogene Proteins c-myc / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sequence Homology, Amino Acid
  • Serine Endopeptidases*
  • Transcription Factors*
  • Transcription, Genetic
  • Tumor Cells, Cultured
  • Tumor Suppressor Proteins
  • beta-Galactosidase / metabolism

Substances

  • Bacterial Proteins
  • Basic Helix-Loop-Helix Leucine Zipper Transcription Factors
  • Basic Helix-Loop-Helix Transcription Factors
  • Basic-Leucine Zipper Transcription Factors
  • DNA, Neoplasm
  • DNA-Binding Proteins
  • LexA protein, Bacteria
  • MAX protein, human
  • MXI1 protein, human
  • Macromolecular Substances
  • Myc associated factor X
  • Oligodeoxyribonucleotides
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • Transcription Factors
  • Tumor Suppressor Proteins
  • beta-Galactosidase
  • Serine Endopeptidases

Associated data

  • GENBANK/L07648
  • GENBANK/L20977
  • GENBANK/L33702
  • GENBANK/L33703
  • GENBANK/L33704
  • GENBANK/L33705
  • GENBANK/L33706
  • GENBANK/L33707
  • GENBANK/L33708
  • GENBANK/L33709