Search results for "regulator"
showing 10 items of 1009 documents
Transcriptional regulation of theNε-fructoselysine metabolism inEscherichia coliby global and substrate-specific cues
2020
AbstractThermally processed food is an important part of the human diet. Heat-treatment, however, promotes the formation of so-called Amadori rearrangement products (ARPs), such as fructoselysine. The gut microbiota includingEscherichia colican utilize these compounds as a nutrient source. While the degradation route for fructoselysine is well described, regulation of the corresponding pathway genesfrlABCDremained poorly understood. Here we use bioinformatics combined with molecular and biochemical analyses and show that inE. coli, fructoselysine metabolism is tightly controlled at the transcriptional level. The global regulator Crp (CAP), as well as the alternative sigma factor σ32 (RpoH) …
Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926
2007
ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of the novel antibiotic dalbavancin. Previous studies have shown that phosphate limitation results in enhanced A40926 production. The A40926 biosynthetic gene ( dbv ) cluster, which consists of 37 genes, encodes two putative regulators, Dbv3 and Dbv4, as well as the response regulator (Dbv6) and the sensor-kinase (Dbv22) of a putative two-component system. Reverse transcription-PCR (RT-PCR) and real-time RT-PCR analysis revealed that the dbv14 - dbv8 and the dbv30 - dbv35 operons, as well as dbv4 , were negatively influenced by phosphate. Dbv4 shows a putative helix-turn-helix DNA-bind…
Antimicrobial and Insecticidal: Cyclic Lipopeptides and Hydrogen Cyanide Produced by Plant-Beneficial Pseudomonas Strains CHA0, CMR12a, and PCL1391 C…
2017
Particular groups of plant-beneficial fluorescent pseudomonads are not only root colonizers that provide plant disease suppression, but in addition are able to infect and kill insect larvae. The mechanisms by which the bacteria manage to infest this alternative host, to overcome its immune system, and to ultimately kill the insect are still largely unknown. However, the investigation of the few virulence factors discovered so far, points to a highly multifactorial nature of insecticidal activity. Antimicrobial compounds produced by fluorescent pseudomonads are effective weapons against a vast diversity of organisms such as fungi, oomycetes, nematodes, and protozoa. Here, we investigated whe…
Regulatory RNAs and beyond.
2011
The dynamic regulation of biological processes by RNA has emerged as a key field in recent years, and was the topic of the 62nd Mosbacher Colloquium of the German Society for Biochemistry and Molecular Biology (GBM). The 2011 Colloquium, held in April in the romantic Neckar-river region, was also a celebration of the tenth anniversary of the RNA Biochemistry study group within the GBM, which acts as platform for RNA biologists and chemists within Germany and in other European countries.
Dynamics of gene regulatory networks and their dependence on network topology and quantitative parameters – the case of phage λ
2019
Background Gene regulatory networks can be modelled in various ways depending on the level of detail required and biological questions addressed. One of the earliest formalisms used for modeling is a Boolean network, although these models cannot describe most temporal aspects of a biological system. Differential equation models have also been used to model gene regulatory networks, but these frameworks tend to be too detailed for large models and many quantitative parameters might not be deducible in practice. Hybrid models bridge the gap between these two model classes – these are useful when concentration changes are important while the information about precise concentrations and binding…
A Decision Support System for Reverse Engineering Gene Regulatory Networks
2009
In this paper we present a knowledge-based system that aims at helping scientists in the reverse engineering process of gene regulatory networks. The main motivation of the proposed approach is to support scientists in the choice of the wide variety of algorithms and methods currently applied in the literature to infer Gene Regulatory Networks starting from gene expression measured using microarray technology. The Decision Support System (DSS) architecture is based on an ontology to model the knowledge base, a logical reasoner that builds the workflow of tasks to be done starting from the user’s request and a set of rules, and, finally, an agenda that runs the algorithms and software schedu…
HIF-1α induces MXI1 by alternate promoter usage in human neuroblastoma cells
2009
Adaptation to low oxygen conditions is essential for maintaining homeostasis and viability in oxygen-consuming multi-cellular tissues, including solid tumors. Central in these processes are the hypoxia-inducible transcription factors, HIF-1 and HIF-2, controlling genes involved in e.g. glucose metabolism and neovascularization. Tumor hypoxia and HIF expression have also been associated with a dedifferentiated phenotype and increased aggressiveness. In this report we show that the MAX interactor-1 (MXI1) gene is directly regulated by HIF proteins in neuroblastoma and breast cancer cells. HIF-binding and transactivation were detected within MXI1 gene regulatory sequences in the vicinity of th…
Alternative Polyadenylation Events Contribute to the Induction of NF-ATc in Effector T Cells
1999
Abstract The transcription factor NF-ATc is synthesized in three prominent isoforms. These differ in the length of their C terminal peptides and mode of synthesis. Due to a switch from the use of a 3′ polyA site to a more proximal polyA site, NF-ATc expression switches from the synthesis of the two longer isoforms in naive T cells to that of short isoform A in T effector cells. The relative low binding affinity of cleavage stimulation factor CstF-64 to the proximal polyA site seems to contribute to its neglect in naive T cells. These alternative polyadenylation events ensure the rapid accumulation of high concentrations of NF-ATc necessary to exceed critical threshold levels of NF-ATc for g…
p63 Isoforms Regulate Metabolism of Cancer Stem Cells
2014
p63 is an important regulator of epithelial development expressed in different variants containing (TA) or lacking (ΔN) the N-terminal transactivation domain. The different isoforms regulate stem-cell renewal and differentiation as well as cell senescence. Several studies indicate that p63 isoforms also play a role in cancer development; however, very little is known about the role played by p63 in regulating the cancer stem phenotype. Here we investigate the cellular signals regulated by TAp63 and ΔNp63 in a model of epithelial cancer stem cells. To this end, we used colon cancer stem cells, overexpressing either TAp63 or ΔNp63 isoforms, to carry out a proteomic study by chemical-labeling …
Autoregulation of NFATc1/A Expression Facilitates Effector T Cells to Escape from Rapid Apoptosis
2002
AbstractThreshold levels of individual NFAT factors appear to be critical for apoptosis induction in effector T cells. In these cells, the short isoform A of NFATc1 is induced to high levels due to the autoregulation of the NFATc1 promoter P1 by NFATs. P1 is located within a CpG island in front of exon 1, represents a DNase I hypersensitive chromatin site, and harbors several sites for binding of inducible transcription factors, including a tandemly arranged NFAT site. A second promoter, P2, before exon 2, is not controlled by NFATs and directs synthesis of the longer NFATc1/B+C isoforms. Contrary to other NFATs, NFATc1/A is unable to promote apoptosis, suggesting that NFATc1/A enhances eff…