Different transcriptional properties of mSim-1 and mSim-2.
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.
Moffett
P
P
Department of Biochemistry, McGill University, 3655 Drummond St., Montreal, Que., Canada.
Pelletier
J
J
D000818:Animals; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D006801:Humans; D018336:Receptors, Aryl Hydrocarbon; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D051792:Basic Helix-Loop-Helix Proteins; D004247:DNA; D017931:DNA Primers; D004268:DNA-Binding Proteins; D018336:Receptors, Aryl Hydrocarbon; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C497396:ARNT protein, human; C490989:ARNT2 protein, human; C491094:SIM1 protein, human; C417032:SIM2 protein, human; C486578:Sim2 protein, mouse