Two novel Drosophila TAF(II)s have homology with human TAF(II)30 and are differentially regulated during development.
TFIID is a multiprotein complex composed of the TATA binding protein (TBP) and TBP-associated factors (TAF(II)s). The binding of TFIID to the promoter is the first step of RNA polymerase II preinitiation complex assembly on protein-coding genes. Yeast (y) and human (h) TFIID complexes contain 10 to 13 TAF(II)s. Biochemical studies suggested that the Drosophila (d) TFIID complexes contain only eight TAF(II)s, leaving a number of yeast and human TAF(II)s (e.g., hTAF(II)55, hTAF(II)30, and hTAF(II)18) without known Drosophila homologues. We demonstrate that Drosophila has not one but two hTAF(II)30 homologues, dTAF(II)16 and dTAF(II)24, which are encoded by two adjacent genes. These two genes are localized in a head-to-head orientation, and their 5' extremities overlap. We show that these novel dTAF(II)s are expressed and that they are both associated with TBP and other bona fide dTAF(II)s in dTFIID complexes. dTAF(II)24, but not dTAF(II)16, was also found to be associated with the histone acetyltransferase (HAT) dGCN5. Thus, dTAF(II)16 and dTAF(II)24 are functional homologues of hTAF(II)30, and this is the first demonstration that a TAF(II)-GCN5-HAT complex exists in Drosophila. The two dTAF(II)s are differentially expressed during embryogenesis and can be detected in both nuclei and cytoplasm of the cells. These results together indicate that dTAF(II)16 and dTAF(II)24 may have similar but not identical functions.
Georgieva
S
S
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, F-67404 Illkirch Cedex, CU de Strasbourg, France.
Kirschner
D B
DB
Jagla
T
T
Nabirochkina
E
E
Hanke
S
S
Schenkel
H
H
de Lorenzo
C
C
Sinha
P
P
Jagla
K
K
Mechler
B
B
Tora
L
L
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000235:genetics*; D004330:Drosophila / Q000196:embryology / Q000235:genetics*; D029721:Drosophila Proteins; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D006801:Humans; D019476:Insect Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; C089768:TAF10 protein, human; D035381:TATA-Binding Protein Associated Factors; C405017:Taf10 protein, Drosophila; C405016:Taf10b protein, Drosophila; D035362:Transcription Factor TFIID; D014157:Transcription Factors