Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20226 (TATA-binding protein)
 1,297 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protein encoded by C-terminal alternatively spliced p53 mRNA (p53as) has been shown previously to occur naturally in mouse cells and to bind sequence-specifically to DNA more efficiently than p53 (p53r, regular form). In the current study, p53as and p53r proteins ectopically expressed in p53-deficient cells each transactivated reporter plasmids containing p53 binding sites. However, p53as consistently was more efficient in transcriptional repression of promoters lacking p53 binding sites and in concentration-dependent repression of the p21(WAF1/Cip-l/Sdi) promoter sequence. The p53as protein, like p53r, associated with TATA-binding protein (TBP), indicating that this interaction does not require the last 26 amino acids of p53. Consistent with its stronger repression effects, p53as interfered with TBP binding to a TATA-containing DNA sequence more efficiently than p53r protein. Taken together, these in vitro and in vivo results demonstrate a novel role in transcriptional repression for a naturally occurring C-terminal variant form of mouse p53 protein associated with differences in DNA binding properties and interference with transcription factor binding.
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PMID:Repression of transcription and interference with DNA binding of TATA-binding protein by C-terminal alternatively spliced p53. 1224 50

We have previously reported that when DNA replication is blocked in some human cell lines, p53 is impaired in its ability to induce a subset of its key target genes, including p21(WAF1/CIP1). Here, we investigated the reason for this impairment by comparing the effects of two agents, hydroxyurea (HU), which arrests cells in early S phase and impairs induction of p21, and daunorubicin, which causes a G(2) block and leads to robust activation of p21 by p53. HU treatment was shown to inhibit p21 mRNA transcription rather than alter its mRNA stability. Nevertheless, chromatin immunoprecipitation assays revealed that HU impacts neither p53 binding nor acetylation of histones H3 and H4 within the p21 promoter. Furthermore, recruitment of the TFIID/TATA-binding protein complex and the large subunit of RNA polymerase II (RNA Pol II) are equivalent after HU and daunorubicin treatments. Relative to daunorubicin treatment, however, transcription elongation of the p21 gene is significantly impaired in cells treated with HU, as evidenced by reduced occupancy of RNA Pol II at regions downstream of the start site. Likewise, in the p21 downstream region after administration of HU, there is less of a specifically phosphorylated form of RNA Pol II (Pol II-C-terminal domain serine 2P) which occurs only when the polymerase is elongating RNA. We propose that while the DNA replication checkpoint is unlikely to regulate the assembly of a p21 promoter initiation complex, it signals to one or more factors involved in the process of transcriptional elongation.
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PMID:p53-Dependent p21 mRNA elongation is impaired when DNA replication is stalled. 1715 27