title: The homeobox-containing Engrailed (En-1) product down-regulates the expression of Pax-6 through a DNA binding-independent mechanism.
abstract: By in situ hybridization of quail neuroretinas, we observed that Engrailed (En-1) is expressed both in the ganglionic and the amacrine cell layers, similarly to Pax-6. Because we observed a decrease of Pax-6 expression in the neuroretina of hatched animals, we studied the effect of the chicken En-1 and En-2 proteins on Pax-6 expression. En-1 and to some extent En-2 were able to repress the basal and the p46Pax-6-activated transcription from the two Pax-6 promoters. Infection of retinal pigmented epithelium by a virus encoding the En-1 protein repressed the endogenous Pax-6, and a similar effect was observed with a homeodomain-deleted En-1. In vitro interaction indicates that En proteins are able to interact with the p46Pax-6 through the paired domain. This interaction negatively regulates the DNA-binding properties of the p46Pax-6. These results suggest an interplay between En-1 and Pax-6 during the central nervous system development and indicate that En-1 may be a negative regulator of Pax-6.
authors.affiliation: Centre National de la Recherche Scientifique EP560, Institut Pasteur, Lille, France.
authors.forename: S
authors.initials: S
authors.lastname: Plaza
authors.forename: M C
authors.initials: MC
authors.lastname: Langlois
authors.forename: N
authors.initials: N
authors.lastname: Turque
authors.forename: S
authors.initials: S
authors.lastname: LeCornet
authors.forename: M
authors.initials: M
authors.lastname: Bailly
authors.forename: A
authors.initials: A
authors.lastname: Bègue
authors.forename: B
authors.initials: B
authors.lastname: Quatannens
authors.forename: C
authors.initials: C
authors.lastname: Dozier
authors.forename: S
authors.initials: S
authors.lastname: Saule
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern; D015153:Blotting, Western; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D015536:Down-Regulation; D005136:Eye Proteins; D018398:Homeodomain Proteins / Q000276:immunology / Q000502:physiology*; D017403:In Situ Hybridization; D009419:Nerve Tissue Proteins / Q000276:immunology / Q000502:physiology*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D011401:Promoter Regions, Genetic / Q000502:physiology; D011784:Quail; D012097:Repressor Proteins; D012160:Retina / Q000196:embryology / Q000378:metabolism; D014157:Transcription Factors; D014162:Transfection; D000099266:Engrailed 2 Protein
chemical_list: D004247:DNA; D004268:DNA-Binding Proteins; D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D014157:Transcription Factors; D000099266:Engrailed 2 Protein