Mediators of activation of fushi tarazu gene transcription by BmFTZ-F1

Mol Cell Biol. 1994 May;14(5):3013-21. doi: 10.1128/mcb.14.5.3013-3021.1994.

Abstract

Transcriptional activation by many eukaryotic sequence-specific regulators appears to be mediated through transcription factors which do not directly bind to DNA. BmFTZ-F1 is a silkworm counterpart of FTZ-F1, a sequence-specific activator of the fushi tarazu gene in Drosophila melanogaster. We report here the isolation of 18- and 22-kDa polypeptides termed MBF1 and MBF2, respectively, that form a heterodimer and mediate activation of in vitro transcription from the fushi tarazu promoter by BmFTZ-F1. Neither MBF1, MBF2, nor a combination of them binds to DNA. MBF1 interacts with BmFTZ-F1 and stabilizes the BmFTZ-F1-DNA complex. MBF1 also makes direct contact with TATA-binding protein (TBP). Both MBF1 and MBF2 are necessary to form a complex between BmFTZ-F1 and TBP. We propose a model in which MBF1 and MBF2 form a bridge between BmFTZ-F1 and TBP and mediate transactivation by stabilizing the protein-DNA interactions.

Publication types

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

MeSH terms

  • Animals
  • Base Sequence
  • Binding Sites
  • Bombyx / genetics
  • Bombyx / metabolism*
  • DNA / metabolism
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism
  • Drosophila Proteins
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism*
  • Fushi Tarazu Transcription Factors
  • Gene Expression
  • Gene Expression Regulation*
  • Homeodomain Proteins*
  • Humans
  • Insect Hormones / biosynthesis*
  • Insect Hormones / genetics
  • Insect Proteins
  • Kinetics
  • Models, Genetic
  • Molecular Sequence Data
  • Molecular Weight
  • Receptors, Cytoplasmic and Nuclear
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Steroidogenic Factor 1
  • TATA Box
  • TATA-Box Binding Protein
  • Transcription Factors / biosynthesis
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*
  • Transcription, Genetic

Substances

  • DNA-Binding Proteins
  • Drosophila Proteins
  • Fushi Tarazu Transcription Factors
  • Homeodomain Proteins
  • Insect Hormones
  • Insect Proteins
  • Receptors, Cytoplasmic and Nuclear
  • Recombinant Proteins
  • Steroidogenic Factor 1
  • TATA-Box Binding Protein
  • Transcription Factors
  • ftz protein, Drosophila
  • nuclear hormone receptor FTZ-F1, Bombyx mori
  • nuclear hormone receptor FTZ-F1, Drosophila
  • DNA