Search results for "Repressor"
showing 10 items of 212 documents
The DNA-binding subunit p140 of replication factor C is upregulated in cycling cells and associates with G 1 phase cell cycle regulatory proteins
1999
The DNA-binding subunit of replication factor C (RFCp140) plays an important role in both DNA replication and DNA repair. The mechanisms regulating activation of RFCp140 thereby controlling replication and cellular proliferation are largely unknown. We analyzed protein expression of RFCp140 during cell cycle progression and investigated the association of RFCp140 with cell cycle regulatory proteins in cell lines of various tissue origin and in primary hematopoietic cells. Western and Northern blot analyses of RFCp140 from synchronized cells showed downregulation of RFCp140 when cells enter a G0-like quiescent state and upregulation of RFCp140 in cycling cells. Translocation from the cytopla…
ENO1 gene product binds to the c-myc promoter and acts as a transcriptional repressor: relationship with Myc promoter-binding protein 1 (MBP-1).
2000
The Myc promoter-binding protein-1 (MBP-1) is a 37-38 kDa protein that binds to the c-myc P2 promoter and negatively regulates transcription of the protooncogene. MBP-1 cDNA shares 97% similarity with the cDNA encoding the glycolytic enzyme alpha-enolase and both genes have been mapped to the same region of human chromosome 1, suggesting the hypothesis that the two proteins might be encoded by the same gene. We show here data indicating that a 37 kDa protein is alternatively translated from the full-length alpha-enolase mRNA. This shorter form of alpha-enolase is able to bind the MBP-1 consensus sequence and to downregulate expression of a luciferase reporter gene under the control of the c…
Targeting positive regulatory domain I-binding factor 1 and X box-binding protein 1 transcription factors by multiple myeloma-reactive CTL.
2005
Abstract Growing evidence indicates that multiple myeloma (MM) and other malignancies are susceptible to CTL-based immune interventions. We studied whether transcription factors inherently involved in the terminal differentiation of mature B lymphocytes into malignant and nonmalignant plasma cells provide MM-associated CTL epitopes. HLA-A*0201 (A2.1) transgenic mice were used to identify A2.1-presented peptide Ag derived from the plasma cell-associated transcriptional regulators, positive regulatory domain I-binding factor 1 (PRDI-BF1) and X box-binding protein 1 (XBP-1). A2.1-restricted CTL specific for PRDI-BF1 and XBP-1 epitopes efficiently killed a variety of MM targets. PRDI-BF1- and X…
Cloning, deletion, and characterization of PadR, the transcriptional repressor of the phenolic acid decarboxylase-encoding padA gene of Lactobacillus…
2004
ABSTRACTLactobacillus plantarumdisplays a substrate-induciblepadAgene encoding a phenolic acid decarboxylase enzyme (PadA) that is considered a specific chemical stress response to the inducing substrate. The putative regulator ofpadAwas located in thepadAlocus based on its 52% identity with PadR, thepadAgene transcriptional regulator ofPediococcus pentosaceus(L. Barthelmebs, B. Lecomte, C. Diviès, and J.-F. Cavin, J. Bacteriol.182:6724-6731, 2000). Deletion of theL. plantarum padRgene clearly demonstrates that the protein it encodes is the transcriptional repressor of divergently orientedpadA. ThepadRgene is cotranscribed with a downstream open reading frame (ORF1), the product of which m…
Efficient Control of raf Gene Expression by CAP and Two Raf Repressors that Bend DNA in Opposite Directions
1999
The plasmid-borne raf operon of Escherichia coli encodes proteins involved in the uptake and utilisation of the trisaccharide raffinose. The operon is subject to dual regulation; to negative control by the binding of RafR repressor to twin operators, O1 and O2, and to positive control by the cAMP-binding protein, CAP. We have identified the CAP binding site (CBS) as a 22 bp palindromic sequence with incomplete dyad symmetry by deletion analysis, DNasel footprinting and electrophoretic mobility shift assays (EMSA) of CAP-DNA complexes. The CBS is centred 60.5 bp upstream of the transcription start point and partially overlaps O1. In vivo, CAP increases rafA (alpha-galactosidase) gene express…
Role of two operators in regulating the plasmid-borne raf operon of Escherichia coli
1994
The plasmid-borne raf operon encodes functions required for the inducible uptake and utilization of raffinose in Escherichia coli K12. The expression of three structural genes for alpha-galactosidase (rafA), Raf permease (rafB) and sucrose hydrolase (rafD) is negatively controlled by the binding of RafR repressor (rafR) to two operator sites, O1 and O2, that flank the -35 sequence of the raf promoter, PA. In vitro, O1 and O2 are occupied on increasing the concentration of RafR, without detectable preference for one site or the other or any indication of cooperative binding. Nucleotide substitutions at positions 3, 4 or 5 in an operator half-site prevented repressor binding, supporting a mod…
Transcription analysis of the genes tcdA-E of the pathogenicity locus of Clostridium difficile.
1997
To analyse the transcription pattern of the five tcdA-E genes of the pathogenicity locus (PaLoc) of Clostridium difficile a protocol was established to purify RNA from strain VPI10463. Transcription analysis of the five tcdA-E genes showed that they were all transcribed. In the early exponential phase, a high level of tcdC and low levels of tcdA,B,D,E transcripts were detectable; this was inverted in the stationary phase, suggesting that TcdC might have a negative influence on transcription of the other genes. Three transcription initiation sites, one for tcdA and two for tcdB were determined by primer extension analysis. Readthrough transcripts from outside the locus were not obtainable, s…
Inducible metabolism of phenolic acids in Pediococcus pentosaceus is encoded by an autoregulated operon which involves a new class of negative transc…
2000
ABSTRACTPediococcus pentosaceusdisplays a substrate-inducible phenolic acid decarboxylase (PAD) activity onp-coumaric acid. Based on DNA sequence homologies between the three PADs previously cloned, a DNA probe of theLactobacillus plantarum pdcgene was used to screen aP. pentosaceusgenomic library in order to clone the corresponding gene of this bacteria. One clone detected with this probe displayed a low PAD activity. Subcloning of this plasmid insertion allowed us to determine the part of the insert which contains a 534-bp open reading frame (ORF) coding for a 178-amino-acid protein presenting 81.5% of identity withL. plantarumPDC enzyme. This ORF was identified as thepadAgene. A second O…
Pseudomonas corrugata crpCDE is part of the cyclic lipopeptide corpeptin biosynthetic gene cluster and is involved in bacterial virulence in tomato a…
2014
Summary: Pseudomonas corrugataCFBP 5454 produces two kinds of cyclic lipopeptides (CLPs), cormycin A and corpeptins, both of which possess surfactant, antimicrobial and phytotoxic activities. In this study, we identified genes coding for a putative non-ribosomal peptide synthetase and an ABC-type transport system involved in corpeptin production. These genes belong to the same transcriptional unit, designated crpCDE. The genetic organization of this locus is highly similar to other PseudomonasCLP biosynthetic clusters. Matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis revealed that transporter and synthetase genomic knock-out mutants were u…
Identification of the mstE Gene Encoding a Glucose-inducible, Low Affinity Glucose Transporter in Aspergillus nidulans
2006
The mstE gene encoding a low affinity glucose transporter active during the germination of Aspergillus nidulans conidia on glucose medium has been identified. mstE expression also occurs in hyphae, is induced in the presence of other repressing carbon sources besides glucose, and is dependent on the function of the transcriptional repressor CreA. The expression of MstE and its subcellular distribution have been studied using a MstE-sGFP fusion protein. Concordant with data on mstE expression, MstE-sGFP is synthesized in the presence of repressing carbon sources, and fluorescence at the periphery of conidia and hyphae is consistent with MstE location in the plasma membrane. Deletion of mstE …