Different transcriptional properties of mSim-1 and mSim-2

FEBS Lett. 2000 Jan 21;466(1):80-6. doi: 10.1016/s0014-5793(99)01750-0.


The mSim-1 and mSim-2 gene products are mammalian homologues of the Drosophila Sim gene. The dSim gene product transactivates through a DNA binding site known as the CNS midline enhancer (CME) element. We have investigated the transcriptional properties of mSIM-1 and mSIM-2 mediated through the CME element in concert with their dimerization partners, ARNT and ARNT-2. The mSIM-1/ARNT heterodimer transactivates reporter constructs via the ARNT carboxy-terminus. However, mSIM-2 quenches ARNT transactivation. We find that mSIM-2 competes with mSIM-1 for binding to ARNT, suggesting a possible antagonism between these transcription factors.

Publication types

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

MeSH terms

  • Animals
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • Base Sequence
  • Basic Helix-Loop-Helix Transcription Factors
  • Binding Sites / genetics
  • Binding, Competitive
  • Cell Line
  • DNA / genetics
  • DNA / metabolism
  • DNA Primers / genetics
  • DNA-Binding Proteins*
  • Helix-Loop-Helix Motifs / genetics
  • Humans
  • Receptors, Aryl Hydrocarbon*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism*
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Transcriptional Activation


  • ARNT protein, human
  • ARNT2 protein, human
  • Basic Helix-Loop-Helix Transcription Factors
  • DNA Primers
  • DNA-Binding Proteins
  • Receptors, Aryl Hydrocarbon
  • Recombinant Proteins
  • Repressor Proteins
  • SIM1 protein, human
  • SIM2 protein, human
  • Sim2 protein, mouse
  • Transcription Factors
  • Aryl Hydrocarbon Receptor Nuclear Translocator
  • DNA