Toutatis, a TIP5-related protein, positively regulates Pannier function during Drosophila neural development.
The GATA factor Pannier (Pnr) activates proneural expression through binding to a remote enhancer of the achaete-scute (ac-sc) complex. Chip associates both with Pnr and with the (Ac-Sc)-Daughterless heterodimer bound to the ac-sc promoters to give a proneural complex that facilitates enhancer-promoter communication during development. Using a yeast two-hybrid screening, we have identified Toutatis (Tou), which physically interacts with both Pnr and Chip. Loss-of-function and gain-of-function experiments indicate that Tou cooperates with Pnr and Chip during neural development. Tou shares functional domains with chromatin remodelling proteins, including TIP5 (termination factor TTFI-interacting protein 5) of NoRC (nucleolar remodelling complex), which mediates repression of RNA polymerase 1 transcription. In contrast, Tou acts positively to activate proneural gene expression. Moreover, we show that Iswi associates with Tou, Pnr and Chip, and is also required during Pnr-driven neural development. The results suggest that Tou and Iswi may belong to a complex that directly regulates the activity of Pnr and Chip during enhancer-promoter communication, possibly through chromatin remodelling.
Vanolst
Luc
L
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Department of Developmental Biology, CNRS/INSERM/ULP, Boite Postale 10142, 67404 Illkirch Cedex, France.
Fromental-Ramain
Catherine
C
Ramain
Philippe
P
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D042002:Chromatin Assembly and Disassembly; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D009420:Nervous System / Q000196:embryology / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D020798:Two-Hybrid System Techniques
C108740:Chi protein, Drosophila; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C109259:pnr protein, Drosophila; D000251:Adenosine Triphosphatases