Molecular cloning, expression, and characterization of the Drosophila 85-kilodalton TFIID subunit.
Transcription initiation factor TFIID is a multimeric protein complex that plays a central role in mediating promoter responses to various activators and repressors. To further understand the role of the 85-kDa TFIID subunit (p85), we have cloned the corresponding cDNA with a probe based on an amino acid sequence of the purified protein. The recombinant p85 interacts directly with both the TATA box-binding subunit (TFIID tau or TBP) and the 110-kDa subunit (p110) of TFIID, suggesting that p85 may play a role in helping to anchor p110 within the TFIID complex and, with other studies, that TFIID assembly and function may involve a concerted series of subunit interactions. Interestingly, the carboxy terminus of p85 contains eight of the WD-40 repeats found originally in the beta subunit of G proteins and more recently in other transcriptional regulatory factors. However, truncated p85 lacking all the WD-40 repeats maintained interactions with both TFIID tau and p110. These observations leave open the possibility of a distinct function for the WD-40 repeats, possibly in transducing signals by interactions with transcriptional regulators and/or other components of the basic transcriptional machinery.
Kokubo
T
T
National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Gong
D W
DW
Yamashita
S
S
Takada
R
R
Roeder
R G
RG
Horikoshi
M
M
Nakatani
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004330:Drosophila / Q000235:genetics*; D015870:Gene Expression; D017344:Genes, Insect; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
D018076:DNA, Complementary; D011994:Recombinant Proteins; D035362:Transcription Factor TFIID; D014157:Transcription Factors