TAFII250 is a bipartite protein kinase that phosphorylates the base transcription factor RAP74.
Some TAF subunits of transcription factor TFIID play a pivotal role in transcriptional activation by mediating protein-protein interactions, whereas other TAFs direct promoter selectivity via protein-DNA recognition. Here, we report that purified recombinant TAFII250 is a protein serine kinase that selectively phosphotylates RAP74 but not other basal transcription factors or common phosphoacceptor proteins. The phosphorylation of RAP74 also occurs in the context of the complete TFIID complex. Deletion analysis revealed that TAFII250 contains two distinct kinase domains each capable of autophosphorylation. However, both the N- and C-terminal kinase domains of TAFII250 are required for efficient transphosphorylation of RAP74 on serine residues. These findings suggest that the targeted phosphorylation of RAP74 by TAFII250 may provide a mechanism for signaling between components within the initiation complex to regulate transcription.
Dikstein
R
R
Howard Hughes Medical Institute, Department of Molecular and Cell Biology University of California, Berkeley, 94720, USA.
Ruppert
S
S
Tjian
R
R
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae; D002460:Cell Line; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D005982:Glutathione Transferase / Q000096:biosynthesis; D051548:Histone Acetyltransferases; D006801:Humans; D007700:Kinetics; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D015183:Restriction Mapping; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014162:Transfection
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D051548:Histone Acetyltransferases; D005982:Glutathione Transferase; D011494:Protein Kinases; C069001:TATA-binding protein associated factor 250 kDa; C056604:transcription factor TFIIF