Conversion of dorsal from an activator to a repressor by the global corepressor Groucho.
The Dorsal morphogen acts as both an activator and a repressor of transcription in the Drosophila embryo to regulate the expression of dorsal/ventral patterning genes. Circumstantial evidence has suggested that Dorsal is an intrinsic activator and that additional factors (corepressors) convert it into a repressor. These corepressors, however, have previously eluded definitive identification. We show here, via the analysis of embryos lacking the maternally encoded Groucho corepressor and via protein-binding assays, that recruitment of Groucho to the template by protein:protein interactions is required for the conversion of Dorsal from an activator to a repressor. Groucho is therefore a critical component of the dorsal/ventral patterning system.
Dubnicoff
T
T
Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, USA.
Valentine
S A
SA
Chen
G
G
Shi
T
T
Lengyel
J A
JA
Paroush
Z
Z
Courey
A J
AJ
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001756:Blastoderm / Q000166:cytology; D004268:DNA-Binding Proteins / Q000502:physiology*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D009687:Nuclear Proteins / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology*; D011485:Protein Binding; D012097:Repressor Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; C062236:dl protein, Drosophila; C091023:gro protein, Drosophila