title: dTAF10- and dTAF10b-Containing Complexes Are Required for Ecdysone-Driven Larval-Pupal Morphogenesis in Drosophila melanogaster.
abstract: In eukaryotes the TFIID complex is required for preinitiation complex assembly which positions RNA polymerase II around transcription start sites. On the other hand, histone acetyltransferase complexes including SAGA and ATAC, modulate transcription at several steps through modification of specific core histone residues. In this study we investigated the function of Drosophila melanogaster proteins TAF10 and TAF10b, which are subunits of dTFIID and dSAGA, respectively. We generated a mutation which eliminated the production of both Drosophila TAF10 orthologues. The simultaneous deletion of both dTaf10 genes impaired the recruitment of the dTFIID subunit dTAF5 to polytene chromosomes, while binding of other TFIID subunits, dTAF1 and RNAPII was not affected. The lack of both dTAF10 proteins resulted in failures in the larval-pupal transition during metamorphosis and in transcriptional reprogramming at this developmental stage. Surprisingly, unlike dSAGA mutations, dATAC subunit mutations resulted in very similar changes in the steady state mRNA levels of approximately 5000 genes as did ablation of both dTaf10 genes, indicating that dTAF10- and/or dTAF10b-containing complexes and dATAC affect similar pathways. Importantly, the phenotype resulting from dTaf10+dTaf10b mutation could be rescued by ectopically added ecdysone, suggesting that dTAF10- and/or dTAF10b-containing complexes are involved in the expression of ecdysone biosynthetic genes. Indeed, in dTaf10+dTaf10b mutants, cytochrome genes, which regulate ecdysone synthesis in the ring gland, were underrepresented. Therefore our data support the idea that the presence of dTAF10 proteins in dTFIID and/or dSAGA is required only at specific developmental steps. We propose that distinct forms of dTFIID and/or dSAGA exist during Drosophila metamorphosis, wherein different TAF compositions serve to target RNAPII at different developmental stages and tissues.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Pahi
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kiss
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
authors.forename: Orbán
authors.initials: O
authors.lastname: Komonyi
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Borsos
authors.affiliation: Institut de Genetique et de Biologie Moleculaire et Cellulaire, Illkirch, France.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Tora
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.|Institute of Biochemistry, Biological Research Center, Szeged, Hungary.
authors.forename: Imre M
authors.initials: IM
authors.lastname: Boros
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Szeged, Szeged, Hungary.|Institute of Biochemistry, Biological Research Center, Szeged, Hungary.
authors.forename: Tibor
authors.initials: T
authors.lastname: Pankotai
mesh_terms: D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000502:physiology*; D004440:Ecdysone / Q000235:genetics / Q000378:metabolism*; D007814:Larva / Q000502:physiology*; D008675:Metamorphosis, Biological / Q000502:physiology*; D009154:Mutation; D011679:Pupa / Q000502:physiology*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism*; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D035381:TATA-Binding Protein Associated Factors; C405017:Taf10 protein, Drosophila; D035362:Transcription Factor TFIID; D004440:Ecdysone