title: Engrailed cooperates with extradenticle and homothorax to repress target genes in Drosophila.
abstract: Engrailed is a key transcriptional regulator in the nervous system and in the maintenance of developmental boundaries in Drosophila, and its vertebrate homologs regulate brain and limb development. Here, we show that the functions of both of the Hox cofactors Extradenticle and Homothorax play essential roles in repression by Engrailed. Mutations that remove either of them abrogate the ability of Engrailed to repress its target genes in embryos, both cofactors interact directly with Engrailed, and both stimulate repression by Engrailed in cultured cells. We suggest a model in which Engrailed, Extradenticle and Homothorax function as a complex to repress Engrailed target genes. These studies expand the functional requirements for extradenticle and homothorax beyond the Hox proteins to a larger family of non-Hox homeodomain proteins.
authors.affiliation: Department of Microbiology and Immunology, Kimmel Cancer Institute, Thomas Jefferson University, Philadelphia, PA 19107, USA.
authors.forename: Masatomo
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Miki
authors.initials: M
authors.lastname: Fujioka
authors.forename: Elena N
authors.initials: EN
authors.lastname: Tolkunova
authors.forename: Deepali
authors.initials: D
authors.lastname: Deka
authors.forename: Muna
authors.initials: M
authors.lastname: Abu-Shaar
authors.forename: Richard S
authors.initials: RS
authors.lastname: Mann
authors.forename: James B
authors.initials: JB
authors.lastname: Jaynes
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000235:genetics; D002478:Cells, Cultured; D004330:Drosophila / Q000166:cytology / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007814:Larva; D009154:Mutation; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D051155:Wnt1 Protein
chemical_list: D029721:Drosophila Proteins; C063459:En protein, Drosophila; D018398:Homeodomain Proteins; D019476:Insect Proteins; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D051155:Wnt1 Protein; C083405:exd protein, Drosophila; C108704:hth protein, Drosophila; C074838:slp1 protein, Drosophila; C074622:wg protein, Drosophila