title: Groucho corepressor functions as a cofactor for the Knirps short-range transcriptional repressor.
abstract: Despite the pervasive roles for repressors in transcriptional control, the range of action of these proteins on cis regulatory elements remains poorly understood. Knirps has essential roles in patterning the Drosophila embryo by means of short-range repression, an activity that is essential for proper regulation of complex transcriptional control elements. Short-range repressors function in a local fashion to interfere with the activity of activators or basal promoters within approximately 100 bp. In contrast, long-range repressors such as Hairy act over distances >1 kb. The functional distinction between these two classes of repressors has been suggested to stem from the differential recruitment of the CtBP corepressor to short-range repressors and Groucho to long-range repressors. Contrary to this differential recruitment model, we report that Groucho is a functional part of the Knirps short-range repression complex. The corepressor interaction is mediated via an eh-1 like motif present in the N terminus and a conserved region present in the central portion of Knirps. We also show that this interaction is important for the CtBP-independent repression activity of Knirps and is required for regulation of even-skipped. Our study uncovers a previously uncharacterized interaction between proteins previously thought to function in distinct repression pathways, and indicates that the Groucho corepressor can be differentially harnessed to execute short- and long-range repression.
authors.affiliation: Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: Sandhya
authors.initials: S
authors.lastname: Payankaulam
authors.forename: David N
authors.initials: DN
authors.lastname: Arnosti
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004330:Drosophila / Q000196:embryology / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000502:physiology; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000235:genetics; D007700:Kinetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010641:Phenotype; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014020:Tissue Extracts / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D004247:DNA; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D012097:Repressor Proteins; D014020:Tissue Extracts; D014157:Transcription Factors; C052837:eve protein, Drosophila; C091023:gro protein, Drosophila; C074089:kni protein, Drosophila