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

Adenovirus E1a proteins function in transcriptional activation, transcriptional repression, cellular DNA synthesis induction, and cellular transformation. Here we examine the role of the previously undefined E1a region 1, the last of three conserved E1a regions to be characterized. Region 1 is required for transcriptional repression, transformation, and DNA synthesis induction, but not transcriptional activation. These results support our previous suggestion that transcriptional repression is the basis of E1a-mediated transformation. Two conserved regions (regions 1 and 2), present in both early E1a proteins, are essential for transcriptional repression, transformation, and induction of DNA synthesis. In contrast, mutagenesis suggests that transcriptional activation requires only 49 amino acids (region 3) unique to the 289 amino acid E1a protein. This we prove by demonstrating that a 49 amino acid region 3 synthetic peptide efficiently activates an E1a-inducible promoter. This peptide is the smallest known protein fragment functioning as a transcriptional activator.
Cell 1987 Sep 25
PMID:Functional domains of adenovirus type 5 E1a proteins. 295 64

Interleukin-2 (IL-2) is a lymphokine synthesized by some T-cells following activation. Resting T-cells do not express IL-2 receptors, but receptors are rapidly expressed on T-cells following interaction of antigens, mitogens, or monoclonal antibodies with the antigen-specific T-cell receptor complex. Using anti-Tac, a monoclonal antibody that recognizes the IL-2 receptor, the receptor has been purified and shown to be a Mr 33,000 peptide that is posttranslationally glycosylated to a Mr 55,000 mature form. Normal resting T-cells and most leukemic T-cell populations do not express IL-2 receptors; however, the leukemic cells of the 11 patients examined who had human T-cell lymphotropic virus-associated adult T-cell leukemia expressed the Tac antigen. In human T-cell lymphotropic virus-I infected cells, the Mr 42,000 long open reading frame protein encoded in part by the pX region of this virus may act as a transacting transcriptional activator that induces IL-2 receptor gene transcription, thus providing an explanation for the constant association of IL-2 receptor expression with adult T-cell lymphotropic virus-I infection of lymphoid cells. The constant expression of large numbers of IL-2 receptors which may be aberrant may play a role in the uncontrolled growth of adult T-cell leukemia cells. Two patients with Tac-positive adult T-cell leukemia have been treated with the anti-Tac. One of the patients had 6- and 3-mo remissions of his leukemia following two courses of therapy with this monoclonal antibody directed toward this growth factor receptor.
Cancer Res 1985 Sep
PMID:Interleukin 2 receptor (Tac antigen) expression in HTLV-I-associated adult T-cell leukemia. 299 Jun 87

As a transcriptional activator, the N protein of phage lambda acts to suppress transcription termination by recognizing a promoter-proximal site, nut, which is separated from the terminators by thousands of base pairs. We demonstrate here that N interacts with the elongating RNA polymerase in transit through the boxB domain of nut. This interaction leads to the stable association of N as an integral component of the transcription apparatus. During subsequent elongation, N translocates along with polymerase through several defined terminators positioned beyond nut. Therefore, by being an operon-specific subunit of the transcription apparatus, N presumably prevents the interaction of polymerase with termination signals.
Cell 1987 Sep 11
PMID:An antitermination protein engages the elongating transcription apparatus at a promoter-proximal recognition site. 304 Feb 63

The murine immediate-early (IE) protein pp89 is a nonstructural virus-encoded phosphoprotein residing in the nucleus of infected cells, where it acts as transcriptional activator. Frequency analysis has shown that in BALB/c mice the majority of virus-specific CTL recognize IE antigens. The present study was performed to assess whether pp89 causes membrane antigen expression detected by IE-specific CTL. Site-directed mutagenesis has been used to delete the introns from gene ieI, encoding pp89, for subsequent integration of the continuous coding sequence into the vaccinia virus genome. After infection with the vaccinia recombinant, the authentic pp89 was expressed in cells that became susceptible to lysis by an IE-specific CTL clone. Priming of mice with the vaccinia recombinant sensitized polyclonal CTL that recognized MCMV-infected cells and transfected cells expressing pp89. Thus, a herpesviral IE polypeptide with essential function in viral transcriptional regulation can also serve as a dominant antigen for the specific CTL response of the host.
J Exp Med 1987 Sep 01
PMID:Cytolytic T lymphocyte recognition of the murine cytomegalovirus nonstructural immediate-early protein pp89 expressed by recombinant vaccinia virus. 304 Aug 84

The UAS (upstream activator sequence) of the yeast PGK gene contains a transcriptional activator domain located between bases -479 and -402 upstream from the initiating ATG. This region of the UAS contains three direct repeats of the sequence 5'CTTCC3'. The roles in transcriptional activation of these repeats and other sequences within the activator domain were investigated. When short regions containing the repeats were removed PGK expression was considerably reduced, the magnitude of the effect depended upon which CTTCC block was absent. Sequences between -473 and -458 which did not contain a CTTCC block were also shown to be necessary for high levels of PGK expression. A DNA fragment containing activator sequences up to -473 was shown to interact specifically in vitro with a yeast nuclear protein extract. DNase I footprinting identified a protected region between -473 and -458 and single base changes in DNase I sensitivity at the CTTCC repeats.
Nucleic Acids Res 1988 Sep 12
PMID:The UAS of the yeast PGK gene is composed of multiple functional elements. 304 80

Many eukaryotic transcriptional activator proteins, including the Xenopus 5S RNA gene activator protein TFIIIA and the HeLa cell protein Sp1, have an approximately 30 amino acid repeating motif which binds to short, specific DNA sequences. Over 150 of these sequences are now known. Based on the observed distribution of amino acid residues, a series of constraints and predictions can be proposed for the structure of the motif. A compatible three-dimensional structural model has been developed by a combination of interactive model building and refinement by molecular dynamics. The model structure consists of a two-stranded beta-hairpin stabilizing a C-terminal alpha-helix by both zinc ligands and hydrophobic interactions. Four of the residue positions on the helix N-terminus and exposed face are predicted to provide base specific ligands. Further implications of the model for DNA binding are discussed.
Protein Eng 1988 Sep
PMID:A model for the tertiary structure of the 28 residue DNA-binding motif ('zinc finger') common to many eukaryotic transcriptional regulatory proteins. 314 34

The initiation of transcription from the nitrogen-regulated promoter glnAp2 requires RNA polymerase containing sigma 54, the transcriptional activator NRI, and the protein kinase NRII, responsible for the conversion of NRI to the active NRI-phosphate. NRI-phosphate does not increase the ability of sigma 54-containing RNA polymerase to bind to the promoter, but rather stimulates the conversion of an initial promoter:polymerase complex to the transcriptionally active open complex. The presence on the DNA template of high-affinity binding sites for NRI/NRI-phosphate, normally located 130 and 100 bp upstream of the site of transcription initiation, results in a 4- to 5-fold lowering of the concentration of NRI required for the formation of the open complex. These high-affinity NRI binding sites facilitate open complex formation when they are moved to positions 700 bp further upstream or 950 bp downstream of glnAp2 on linear DNA templates.
Cell 1987 Sep 25
PMID:Initiation of transcription at the bacterial glnAp2 promoter by purified E. coli components is facilitated by enhancers. 330 60

Expression of the Escherichia coli maltose regulon is controlled by MalT, a transcriptional activator (Mr = 102,288) encoded by the malT gene. Activation of transcription depends on the presence of the inducer, maltotriose. Using an in vitro transcription/translation assay to monitor the protein, we have purified MalT in native form from MalT-overproducing bacteria. The purified protein is able to promote transcription from different MalT-controlled promoters in well-defined in vitro systems. Maltotriose and the MalT protein suffice to stimulate initiation of transcription at malPp by the E. coli RNA polymerase holoenzyme. In contrast, both MalT protein and cAMP receptor protein are required with their respective effectors, maltotriose and cyclic AMP, for activation of malEp. These data are in agreement with in vivo observations. In addition, we present evidence that MalT is an ATP-binding protein, a result suggesting that ATP may play a role in transcription initiation.
J Biol Chem 1987 Sep 15
PMID:Purification and properties of the MalT protein, the transcription activator of the Escherichia coli maltose regulon. 330 11

UV light can serve as a molecular probe to identify DNA-protein interactions at nucleotide level resolution from intact yeast cells. We have used the photofootprinting technique to determine during which of three regulated states (uninduced, induced, and catabolite repressed) the transcriptional activator protein encoded by GAL4 binds to its recognition sites within the GAL1-GAL10 upstream activating sequence (UASG). GAL4 protein is bound to at least four, and probably five, related sequence blocks within UASG under both induced and uninduced states. GAL4-dependent photofootprints are lost under conditions of catabolite repression. We observed no footprint patterns unique to catabolite-repressed cells, which suggests that binding of a repressor to the UASG is not involved in this process. Photofootprints of the GAL10 TATA element are strictly correlated with transcription: uninduced, catabolite-repressed, and delta gal4 cells exhibit footprints characteristic of the inactive promoter; induced and delta gal80 cells, which express GAL10 constitutively, display footprints unique to the actively transcribed gene.
Mol Cell Biol 1987 Sep
PMID:In vivo DNA-binding properties of a yeast transcription activator protein. 331 11

A number of in-frame insertion and deletion mutations have been constructed in vitro in the Klebsiella pneumoniae ntrB gene and the effects of each mutant NtrB protein on NtrC activity have been assessed after reintroduction of the ntrB mutation into the glnA ntrBC operon. These experiments suggest that the phosphorylation of NtrC catalysed by NtrB not only makes NtrC competent as a transcriptional activator but also improves the DNA-binding properties and hence the negative control functions of NtrC. The variety of NtrB phenotypes obtained suggest a structure/function model for the protein.
Mol Microbiol 1987 Sep
PMID:Analysis of the Klebsiella pneumoniae ntrB gene by site-directed in vitro mutagenesis. 332 95


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>