Homeodomain interaction with the beta subunit of the general transcription factor TFIIE.
Homeodomain-containing proteins play a crucial role as transcriptional regulators in the process of cell differentiation. The homeodomain performs a dual function in this regard, acting as a DNA binding domain and participating in protein-protein interactions that enhance DNA binding specificity or regulatory activity. Here we describe a homeodomain class-specific interaction with the beta subunit of the general transcription factor TFIIE. We show that the Antennapedia and Abdominal-B homeodomains bind to TFIIEbeta, but the even-skipped homeodomain does not. Using a two-hybrid assay performed in cultured cells, we demonstrate that the homeodomain-TFIIEbeta interaction occurs in vivo. The Abdominal-B homeodomain is shown to activate transcription in vitro, and this activation can be blocked with anti-TFIIEbeta antibody without affecting basal transcription levels. Together with published data demonstrating an interaction between proteins containing even-skipped class homeodomains and the TATA-binding protein (Um, M., Li, C., and Manley, J. L. (1995) Mol. Cell. Biol. 15, 5007-5016; Zhang, H., Catron, K. M., and Abate-Shen, C. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 1764-1769), these results suggest various homeodomain containing proteins interact with different general transcription factors, an observation that may have important implications for transcriptional regulation.
Zhu
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Department of Biological Sciences, University of Pittsburgh, A234 Langley Hall, Pittsburgh, Pennsylvania 15260, USA.
Kuziora
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MA
D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII; D014158:Transcription, Genetic
D017931:DNA Primers; D018398:Homeodomain Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; C066644:transcription factor TFIIE; D005982:Glutathione Transferase