Drosophila 230-kD TFIID subunit, a functional homolog of the human cell cycle gene product, negatively regulates DNA binding of the TATA box-binding subunit of TFIID.
A Drosophila cDNA encoding the largest TFIID subunit (p230) was isolated using a degenerate oligodeoxynucleotide probe based on an amino acid sequence of the purified protein. The entire cDNA sequence contains an open reading frame encoding a polypeptide of 2068 amino acids, corresponding to a calculated molecular mass of 232 kD. The deduced amino acid sequence showed a strong sequence similarity with the protein encoded by a human gene (CCG1) implicated in cell cycle progression through G1, suggesting that p230 may be a target for cell cycle regulatory factors. The recombinant protein expressed in Sf9 cells via a baculovirus vector interacts directly with the TATA box-binding subunit of TFIID (TFIID tau or TBP) from Drosophila, human, and yeast. Surprisingly, recombinant p230 inhibits the TATA box-binding activity and function of TFIID tau, suggesting that p230 interactions with TFIID tau, and possible modulations thereof by other factors may play an important role in TFIID function.
Kokubo
T
T
National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Gong
D W
DW
Yamashita
S
S
Horikoshi
M
M
Roeder
R G
RG
Nakatani
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle / Q000235:genetics; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000737:chemistry / Q000196:embryology / Q000235:genetics*; D016193:G1 Phase / Q000235:genetics; D006609:High Mobility Group Proteins / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D016385:TATA Box; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*
D004268:DNA-Binding Proteins; D006609:High Mobility Group Proteins; D010446:Peptide Fragments; D035181:TATA-Box Binding Protein; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D004247:DNA