Transcriptional activity of pannier is regulated negatively by heterodimerization of the GATA DNA-binding domain with a cofactor encoded by the u-shaped gene of Drosophila.
The genes pannier (pnr) and u-shaped (ush) are required for the regulation of achaete-scute during establishment of the bristle pattern in Drosophila. pnr encodes a protein belonging to the GATA family of transcription factors, whereas ush encodes a novel zinc finger protein. Genetic interactions between dominant pnr mutants bearing lesions situated in the amino-terminal zinc finger of the GATA domain and ush mutants have been described. We show here that both wild-type Pannier and the dominant mutant form activate transcription from the heterologous alpha globin promoter when transfected into chicken embryonic fibroblasts. Furthermore, Pnr and Ush are found to heterodimerize through the amino-terminal zinc finger of Pnr and when associated with Ush, the transcriptional activity of Pnr is lost. In contrast, the mutant pnr protein with lesions in this finger associates only poorly with Ush and activates transcription even when cotransfected with Ush. These interactions have been investigated in vivo by overexpression of the mutant and wild-type proteins. The results suggest an antagonistic effect of Ush on Pnr function and reveal a new mode of regulation of GATA factors during development.
Haenlin
M
M
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale/Université Louis Pasteur, 67404 Illkirch Cedex, France.
Cubadda
Y
Y
Blondeau
F
F
Heitzler
P
P
Lutz
Y
Y
Simpson
P
P
Ramain
P
P
D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D002645:Chickens; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000502:physiology*; D019281:Dimerization; D015536:Down-Regulation; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D005914:Globins / Q000235:genetics; D019476:Insect Proteins / Q000502:physiology*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins / Q000235:genetics*; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C109259:pnr protein, Drosophila; C109258:ush protein, Drosophila; D005914:Globins