Search results for "Prom"

Fen1 is induced p53 dependently and involved in the recovery from UV-light-induced replication inhibition.

2005

Mouse embryonic fibroblasts (MEFs) that lack p53 are hypersensitive to the cytotoxic and genotoxic effect of ultraviolet (UV-C) light. They also display a defect in the recovery from UV-C-induced DNA replication inhibition. An enzyme involved in processing stalled DNA replication forks is flap endonuclease 1 (Fen1). Gene expression profiling of UV-C-irradiated MEFs revealed fen1 to be upregulated, which was confirmed by RT-PCR and Western blot experiments. Increased Fen1 levels upon UV-C exposure are due to transcriptional activation, as revealed by inhibitor studies. Fen1 induction was dose- and time-dependent; it occurred on protein level already 3 h after irradiation. Induction of Fen1 b…

Synergism between the components of the bipartite major immediate-early transcriptional enhancer of murine cytomegalovirus does not accelerate virus …

2009

Major immediate-early (MIE) transcriptional enhancers of cytomegaloviruses are key regulators that are regarded as determinants of virus replicative fitness and pathogenicity. The MIE locus of murine cytomegalovirus (mCMV) shows bidirectional gene-pair architecture, with a bipartite enhancer flanked by divergent core promoters. Here, we have constructed recombinant viruses mCMV-ΔEnh1 and mCMV-ΔEnh2 to study the impact of either enhancer component on bidirectional MIE gene transcription and on virus replication in cell culture and various host tissues that are relevant to CMV disease. The data revealed that the two unipartite enhancers can operate independently, but synergize in enhancing MI…

The APC/C cofactor Cdh1 prevents replicative stress and p53-dependent cell death in neural progenitors

2013

The E3-ubiquitin ligase APC/C-Cdh1 is essential for endoreduplication but its relevance in the mammalian mitotic cell cycle is still unclear. Here we show that genetic ablation of Cdh1 in the developing nervous system results in hypoplastic brain and hydrocephalus. These defects correlate with enhanced levels of Cdh1 substrates and increased entry into the S phase in neural progenitors. However, cell division is prevented in the absence of Cdh1 due to hyperactivation of cyclin-dependent kinases, replicative stress, induction of p53, G2 arrest and apoptotic death of these progenitor cells. Concomitant ablation of p53 rescues apoptosis but not replicative stress, resulting in the presence of …

DAZAP2 acts as specifier of the p53 response to DNA damage.

2021

Abstract The DNA damage-responsive tumor suppressors p53 and HIPK2 are well established regulators of cell fate decision-making and regulate the cellular sensitivity to DNA-damaging drugs. Here, we identify Deleted in Azoospermia-associated protein 2 (DAZAP2), a small adaptor protein, as a novel regulator of HIPK2 and specifier of the DNA damage-induced p53 response. Knock-down or genetic deletion of DAZAP2 strongly potentiates cancer cell chemosensitivity both in cells and in vivo using a mouse tumour xenograft model. In unstressed cells, DAZAP2 stimulates HIPK2 polyubiquitination and degradation through interplay with the ubiquitin ligase SIAH1. Upon DNA damage, HIPK2 site-specifically ph…

Expression in Streptomyces lividans of Nonomuraea genes cloned in an artificial chromosome

2004

A bacterial artificial chromosomal library of Nonomuraea sp. ATCC39727 was constructed using Escherichia coli-Streptomyces artificial chromosome (ESAC) and screened for the presence of dbv genes known to be involved in the biosynthesis of the glycopeptide A40926. dbv genes were cloned as two large, partially overlapping, fragments and transferred into the host Streptomyces lividans, thus generating strains S. lividansColon, two colonsNmESAC50 and S. lividansColon, two colonsNmESAC57. The heterologous expression of Nonomuraea genes in S. lividans was successfully demonstrated by using combined RT-PCR and proteomic approaches. MALDI-TOF analysis revealed that a Nonomuraea ABC transporter is e…

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…

Growth phase-dependent regulation of nuoA-N expression in Escherichia coli K-12 by the Fis protein: upstream binding sites and bioenergetic significa…

2000

The expression of the nuoA-N operon of Escherichia coli K-12, which encodes the proton-pumping NADH dehydrogenase I is modulated by growth phase-dependent regulation. Under respiratory growth conditions, expression was stimulated in early exponential, and to a lesser extent in late exponential and stationary growth phases. The stimulation in the early exponential growth phase was not observed in fis mutants, which are deficient for the growth phase-responsive regulator Fis. Neither the alternative sigma factor RpoS nor the integration host factor (IHF) are involved in growth phase-dependent regulation of this operon. When incubated with nuo promoter DNA, isolated Fis protein formed three re…

Requirement of the Lactobacillus casei MaeKR two-component system for L-malic acid utilization via a malic enzyme pathway.

2009

ABSTRACTLactobacillus caseican metabolizel-malic acid via malolactic enzyme (malolactic fermentation [MLF]) or malic enzyme (ME). Whereas utilization ofl-malic acid via MLF does not support growth, the ME pathway enablesL. caseito grow onl-malic acid. In this work, we have identified in the genomes ofL. caseistrains BL23 and ATCC 334 a cluster consisting of two diverging operons,maePEandmaeKR, encoding a putative malate transporter (maeP), an ME (maeE), and a two-component (TC) system belonging to the citrate family (maeKandmaeR). Homologous clusters were identified inEnterococcus faecalis,Streptococcus agalactiae,Streptococcus pyogenes, andStreptococcus uberis. Our results show that ME is …

Multiple Site-Specific Binding of Fis Protein to Escherichia coli nuoA-N Promoter DNA and its Impact on DNA Topology Visualised by Means of Scanning …

2004

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…