Two different Drosophila ADA2 homologues are present in distinct GCN5 histone acetyltransferase-containing complexes.
We have isolated a novel Drosophila (d) gene coding for two distinct proteins via alternative splicing: a homologue of the yeast adaptor protein ADA2, dADA2a, and a subunit of RNA polymerase II (Pol II), dRPB4. Moreover, we have identified another gene in the Drosophila genome encoding a second ADA2 homologue (dADA2b). The two dADA2 homologues, as well as many putative ADA2 homologues from different species, all contain, in addition to the ZZ and SANT domains, several evolutionarily conserved domains. The dada2a/rpb4 and dada2b genes are differentially expressed at various stages of Drosophila development. Both dADA2a and dADA2b interacted with the GCN5 histone acetyltransferase (HAT) in a yeast two-hybrid assay, and dADA2b, but not dADA2a, also interacted with Drosophila ADA3. Both dADA2s further potentiate transcriptional activation in insect and mammalian cells. Antibodies raised either against dADA2a or dADA2b both immunoprecipitated GCN5 as well as several Drosophila TATA binding protein-associated factors (TAFs). Moreover, following glycerol gradient sedimentation or chromatographic purification combined with gel filtration of Drosophila nuclear extracts, dADA2a and dGCN5 were detected in fractions with an apparent molecular mass of about 0.8 MDa whereas dADA2b was found in fractions corresponding to masses of at least 2 MDa, together with GCN5 and several Drosophila TAFs. Furthermore, in vivo the two dADA2 proteins showed different localizations on polytene X chromosomes. These results, taken together, suggest that the two Drosophila ADA2 homologues are present in distinct GCN5-containing HAT complexes.
Muratoglu
Selen
S
Institute of Biochemistry, University of Szeged, Hungary.
Georgieva
Sofia
S
Pápai
Gábor
G
Scheer
Elisabeth
E
Enünlü
Izzet
I
Komonyi
Orbán
O
Cserpán
Imre
I
Lebedeva
Lubov
L
Nabirochkina
Elena
E
Udvardy
Andor
A
Tora
László
L
Boros
Imre
I
D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D004625:Embryo, Nonmammalian; D018507:Gene Expression Regulation, Developmental; D051548:Histone Acetyltransferases; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D005810:Multigene Family; D012319:RNA Polymerase II / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation; D000099224:p300-CBP-Associated Factor
D000123:Acetyltransferases; D029721:Drosophila Proteins; D051548:Histone Acetyltransferases; D046911:Macromolecular Substances; D012319:RNA Polymerase II; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; C090575:ADA2 protein, S cerevisiae; C470558:Ada2a protein, Drosophila; C083323:NGG1 protein, S cerevisiae; C089768:TAF10 protein, human; C470559:ADA3 protein, Drosophila; C470557:GCN5 protein, Drosophila; D000099224:p300-CBP-Associated Factor; C423309:RPB4 protein, S cerevisiae