title: Engrailed homeoprotein acts as a signaling molecule in the developing fly.
abstract: Homeodomain transcription factors classically exert their morphogenetic activities through the cell-autonomous regulation of developmental programs. In vertebrates, several homeoproteins have also been shown to have direct non-cell-autonomous activities in the developing nervous system. We present the first in vivo evidence for homeoprotein signaling in Drosophila. Focusing on wing development as a model, we first demonstrate that the homeoprotein Engrailed (En) is secreted. Using single-chain anti-En antibodies expressed under the control of a variety of promoters, we delineate the wing territories in which secreted En acts. We show that En is a short-range signaling molecule that participates in anterior crossvein development, interacting with the Dpp signaling pathway. This report thus suggests that direct signaling with homeoproteins is an evolutionarily conserved phenomenon that is not restricted to neural tissues and involves interactions with bona fide signal transduction pathways.
authors.affiliation: Institut de Génétique Humaine, CNRS, UPR 1142, 141 rue de la Cardonille, 34396 Montpellier, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Layalle
authors.forename: Michel
authors.initials: M
authors.lastname: Volovitch
authors.forename: Bruno
authors.initials: B
authors.lastname: Mugat
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bonneaud
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Parmentier
authors.forename: Alain
authors.initials: A
authors.lastname: Prochiantz
authors.forename: Alain
authors.initials: A
authors.lastname: Joliot
authors.forename: Florence
authors.initials: F
authors.lastname: Maschat
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000906:Antibodies; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D057809:HEK293 Cells; D018398:Homeodomain Proteins / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D015398:Signal Transduction; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*; D014921:Wings, Animal / Q000196:embryology* / Q000378:metabolism
chemical_list: D000906:Antibodies; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C064196:dpp protein, Drosophila; C106185:engrailed homeobox proteins