Interaction with RAP74 subunit of TFIIF is required for transcriptional activation by serum response factor.
A few general transcription factors, in particular TFIID and TFIIB, have been found to bind transcriptional activators. Here we show that the general transcription factor TFIIF is also a target for a transcriptional activator, namely serum response factor (SRF), which binds to the c-fos promoter. Using a yeast interaction assay, we find that SRF binds the RAP74 subunit of TFIIF and that SRF's transcriptional activation domain is the region involved in this binding. Further, RAP74's central charged cluster domain is required for binding to SRF's activation domain. Deletion of this domain impairs RAP74's ability to support SRF-activated transcription in vitro but has little effect on the protein's basal transcription activity or its ability to support SP1-activated transcription. The correlation of SRF-RAP74 binding with transcriptional activation suggests that RAP74 is a critical target for SRF-activated transcription.
Department of Biological Sciences, Columbia University, New York, New York 10027.
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Joliot
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Demma
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Prywes
D016475:3T3 Cells; D000818:Animals; D001665:Binding Sites; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D026362:Serum Response Factor; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; D026362:Serum Response Factor; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C056604:transcription factor TFIIF