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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The simian virus 40 large T antigen is a promiscuous transcriptional activator of many viral and cellular promoters. We show that the promoter structure necessary for T antigen-mediated transcriptional activation is very simple. A TATA or initiator element is required, in addition to an upstream factor-binding site, which can be quite variable. We found that promoters containing an SP1-, ATF-, AP1-, or TEF-I-binding site, in conjunction with a TATA element, can all be activated in the presence of T antigen. In addition, preference for specific TATA elements was indicated. Promoters containing the HSP70 TATA element functioned better than those with the adenovirus E2 TATA element, while promoters containing the simian virus 40 (SV40) early TATA element failed to be activated. In addition, simple promoters containing the initiator element from the terminal deoxynucleotidyltransferase gene could be activated by T antigen. The SV40 late promoter, a primary target for T antigen transcriptional activation, conforms to this simple promoter structure. The region from which most late transcripts initiate contains a cluster of initiator-like elements (SV40 nucleotides [nt] 250 to 335) forming an initiator region (IR). This lies downstream of the previously described octamer-TEF element (SV40 nt 199 to 218) which contains the TEF-I-binding sites shown to be necessary for T antigen-mediated transcriptional activation of the late promoter. We show that a simple late promoter made up of IR sequences and octamer-TEF element-containing sequences is transcriptionally activated by T antigen. These experiments also showed that specific sequences in the IR, SV40 nt 272 to 294, are particularly important for late promoter activation. Previous findings (M. C. Gruda, J. M. Zablotny, J. H. Xiao, I. Davidson, and J. C. Alwine, Mol. Cell. Biol. 13:961-969, 1993) suggested that T antigen could mediate transcriptional activation through interaction with the TATA-binding protein, as well as upstream bound transcription factors. Our present data are predicted by this model and suggest that at least one mechanism by which the T antigen manifests promiscuous transcriptional activation is its ability to interact with numerous transcription factors in a simple promoter context.
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PMID:Transcriptional activation by simian virus 40 large T antigen: requirements for simple promoter structures containing either TATA or initiator elements with variable upstream factor binding sites. 841 70

DBP, HLF and TEF comprise a distinct subfamily of mammalian bZIP proteins that plays an important role in regulation of tissue-specific gene expression, particularly in the liver. In this report we demonstrate that DBP contains a 38 amino acid TAD which is highly homologous to the HLF and TEF TADs that we have delineated previously. Deletion of this domain completely abrogates transcriptional activity of native DBP and GAL4-DBP fusion proteins. This domain functions as a modular TAD that is a potent transcriptional activator when fused to the GAL4 DBD. While DBP itself is a liver-specific transactivator, the DBP TAD is active in a variety of cell types, indicating that liver-specific activity is not an intrinsic property of the TAD and must be conferred by other regions of the protein. Using GAL4-HLF fusion proteins, we further refine the core TAD of PAR proteins to a region of 13 amino acids. Recently described PAR-bZIP proteins from Drosophila and zebrafish also contain domains that share strong homology with the TAD of mammalian PAR proteins, making this one of the most highly evolutionarily conserved TADs identified to date.
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PMID:The DBP transcriptional activation domain is highly homologous to that of HLF and TEF and is not responsible for the tissue type-specific transcriptional activity of DBP. 1122 63