Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The X. laevis tRNA((Ser)Sec) gene is different from the other tRNA genes in that its promoter contains two external elements, a PSE and a TATA box functionally equivalent to those of the U6 snRNA gene. Of the two internal promoters governing classical tRNA gene transcription, only subsists the internal B box. In this report, we show that the tRNA((Ser)Sec) contains in addition an activator element (AE) which we have mapped by extensive mutagenesis. Activation is only dependent on a 15 bp fragment residing between -209 and -195 and containing an SPH motif. In vitro, this element forms a complex with a nuclear protein which is different from the TEF-1 transcriptional activator that binds the SV40 Sph motifs. This AE is versatile since it shows capacity of activating a variety of genes in vivo, including U1 and U6 snRNAs and HSV thymidine kinase. Unexpectedly for an snRNA-related gene, the tRNA((Ser)Sec) is deprived of octamer or octamer-like motifs. The X.laevis tRNA((Ser)Sec) gene represents the first example of a Pol III snRNA-type gene whose activation of transcription is completely octamer-independent.
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PMID:Optimal tRNA((Ser)Sec) gene activity requires an upstream SPH motif. 131 Oct 68

Simian virus 40 (SV40) large T antigen is a promiscuous transcriptional activator of many viral and cellular promoters. The SV40 late promoter, a primary target for T-antigen transcriptional activation, contains a previously described T-antigen-activatable binding site (SV40 nucleotides 186 to 225). The T-antigen-activatable binding site element contains overlapping octamer (Oct)- and SPH (TEF-1)-binding sites (Oct/SPH site). Using this Oct/SPH site as an upstream element in a simple promoter, we show that the SPH sites are necessary for transcriptional activation by T antigen. In addition, we show that when Oct 1 is overproduced, it can eliminate T-antigen-mediated transcriptional activation, as well as basal activity, from the simple Oct/SPH promoter as well as the intact SV40 late promoter. This suggests that one function of T antigen in transcriptional activation of the late promoter is to alter factor binding at the Oct/SPH region to favor binding of factors to the SPH sites.
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PMID:Simian virus 40 (SV40) T-antigen transcriptional activation mediated through the Oct/SPH region of the SV40 late promoter. 164 83

Transcriptional activation and repression of the vascular smooth muscle (VSM) alpha-actin gene in myoblasts and fibroblasts is mediated, in part, by positive and negative elements contained within an approximately 30-bp polypurine-polypyrimidine tract. This region contains binding sites for an essential transcription-activating protein, identified as transcriptional enhancer factor I (TEF-1), and two tissue-restrictive, sequence-specific, single-stranded-DNA-binding activities termed VACssBF1 and VACssBF2. TEF-1 has no detectable single-stranded-DNA-binding activity, while VACssBF1 and VACssBF2 have little, if any, affinity for double-stranded DNA. Site-specific mutagenesis experiments demonstrate that the determinants of VACssBF1 and VACssBF2 binding lie on opposite strands of the DNA helix and include the TEF-1 recognition sequence. Functional analysis of this region reveals that the CCAAT box-binding protein nuclear factor Y (NF-Y) can substitute for TEF-1 in activating VSM alpha-actin transcription but that the TEF-1-binding site is essential for the maintenance of full transcriptional repression. Importantly, replacement of the TEF-1-binding site with that for NF-Y diminishes the ability of VACssBF1 and VACssBF2 to bind to separated single strands. Additional activating mutations have been identified which lie outside of the TEF-1-binding site but which also impair single-stranded-DNA-binding activity. These data support a model in which VACssBF1 and VACssBF2 function as repressors of VSM alpha-actin transcription by stabilizing a local single-stranded-DNA conformation, thus precluding double-stranded-DNA binding by the essential transcriptional activator TEF-1.
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PMID:Negative regulation of the vascular smooth muscle alpha-actin gene in fibroblasts and myoblasts: disruption of enhancer function by sequence-specific single-stranded-DNA-binding proteins. 773 27