Active repression of transcription by the engrailed homeodomain protein.
The Drosophila engrailed gene product (En) is a homeodomain-containing protein that contributes to segmental patterning. In transfection assays it acts as a transcriptional repressor. We show that En is an active repressor, blocking activation by mammalian and yeast activators that bind to sites some distance away from those bound by En. Active repression is distinct from the effects of passive homeodomain-containing proteins, which repress when competing with activators for binding sites and activate when competing with En. Active repression activity maps outside the En homeodomain, and this activity can be transferred to a heterologous DNA binding domain.
Department of Biochemistry and Biophysics, University of California, San Francisco 94143.
J B
JB
Jaynes
P H
PH
O'Farrell
D000818:Animals; D004268:DNA-Binding Proteins / Q000502:physiology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics*; D046911:Macromolecular Substances; D016133:Polymerase Chain Reaction; D012045:Regulatory Sequences, Nucleic Acid; D012097:Repressor Proteins; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D007301:Insect Hormones; D046911:Macromolecular Substances; D012097:Repressor Proteins; D014157:Transcription Factors