Search results for "G proteins"

showing 10 items of 992 documents

Defective Postnatal Neurogenesis and Disorganization of the Rostral Migratory Stream in Absence of theVax1Homeobox Gene

2004

The subventricular zone (SVZ) is one of the sources of adult neural stem cells (ANSCs) in the mouse brain. Precursor cells proliferate in the SVZ and migrate through the rostral migratory stream (RMS) to the olfactory bulb (OB), where they differentiate into granule and periglomerular cells. Few transcription factors are known to be responsible for regulating NSC proliferation, migration, and differentiation processes; even fewer have been found to be responsible for the organization of the SVZ and RMS. For this reason, we studied the ventral anterior homeobox (Vax1) gene in NSC proliferation and in SVZ organization. We found thatVax1is strongly expressed in the SVZ and in the RMS and that,…

TelencephalonRostral migratory streamanimal diseasesCellular differentiationDevelopment/Plasticity/RepairSubventricular zoneMice TransgenicNerve Tissue ProteinsBiologyMiceCell MovementPrecursor cellmedicineAnimalsCell ProliferationHomeodomain ProteinsMice KnockoutStem CellsGeneral NeuroscienceNeuropeptidesGenes HomeoboxGene Expression Regulation DevelopmentalCell DifferentiationOlfactory BulbNeural stem cellOlfactory bulbDNA-Binding Proteinsmedicine.anatomical_structurenervous systemStem cellEpendymaNeuroscienceTranscription FactorsThe Journal of Neuroscience
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Glutathione regulates telomerase activity in 3T3 fibroblasts.

2004

Changes in telomerase activity have been associated either with cancer, when activity is increased, or with cell cycle arrest when it is decreased. We report that glutathione, a physiological antioxidant present at high intracellular concentrations, regulates telomerase activity in cells in culture. Telomerase activity increases in 3T3 fibroblasts before exponential cell growth. The peak of telomerase activity takes place 24 h after plating and coincides with the maximum levels of glutathione in the cells. When cells are treated with buthionine sulfoximine, which decreases glutathione levels in cells, telomerase activity decreases by 60%, and cell growth is delayed. Glutathione depletion in…

TelomeraseAntioxidantCell cycle checkpointTime FactorsCell divisionmedicine.medical_treatmentBlotting WesternImmunoblottingE2F4 Transcription FactorBiochemistryGene Expression Regulation Enzymologicchemistry.chemical_compoundMicemedicineAnimalsButhionine sulfoximineColoring AgentsMolecular BiologyButhionine SulfoximineTelomeraseInhibitor of Differentiation Protein 2Cell growthCell CycleCell BiologyGlutathione3T3 CellsTrypan BlueCell cycleFibroblastsFlow CytometryMolecular biologyGlutathioneDNA-Binding ProteinsRepressor ProteinschemistryOxidation-ReductionCell DivisionTranscription FactorsThe Journal of biological chemistry
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A homolog of the putative tumor suppressor QM in the sponge Suberites domuncula: downregulation during the transition from immortal to mortal (apopto…

1999

Abstract The activation of components of the transcription factors such as AP-1 or c-jun is essential for a physiological response of metazoan cells during aging. The activity of such proto-oncoproteins is under enzymatic control. The function of c-jun is additionally modulated by the QM protein. Here, we studied the expression of the gene, encoding the QM-like protein in the sponge Suberites domuncula . These animals contain high levels of telomerase in their somatic cells. To understand the switch from telomerase-positive immortal cells to telomerase-negative mortal cells which undergo apoptosis, the expression of the QM-like gene was measured in this system. The cDNA, termed QMSD , encod…

TelomeraseMolecular Sequence DataDown-RegulationGene ExpressionApoptosisDownregulation and upregulationComplementary DNAAnimalsHumansAmino Acid SequenceRNA MessengerCloning MolecularTranscription factorGenePhylogenyBase Sequencebiologyc-junProteinsRNA-Binding ProteinsCell BiologyGeneral Medicinebiology.organism_classificationMolecular biologyPoriferaSuberites domunculaOpen reading frameProtein BiosynthesisCarrier ProteinsDevelopmental BiologyTissue and Cell
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Chromatin modifiers and recombination factors promote a telomere fold-back structure, that is lost during replicative senescence.

2020

Telomeres have the ability to adopt a lariat conformation and hence, engage in long and short distance intra-chromosome interactions. Budding yeast telomeres were proposed to fold back into subtelomeric regions, but a robust assay to quantitatively characterize this structure has been lacking. Therefore, it is not well understood how the interactions between telomeres and non-telomeric regions are established and regulated. We employ a telomere chromosome conformation capture (Telo-3C) approach to directly analyze telomere folding and its maintenance in S. cerevisiae. We identify the histone modifiers Sir2, Sin3 and Set2 as critical regulators for telomere folding, which suggests that a dis…

TelomeraseProtein Folding:Chemicals and Drugs::Amino Acids Peptides and Proteins::Proteins::DNA-Binding Proteins::Rad52 DNA Repair and Recombination Protein [Medical Subject Headings]:Chemicals and Drugs::Amino Acids Peptides and Proteins::Proteins::Fungal Proteins::Saccharomyces cerevisiae Proteins [Medical Subject Headings]Gene ExpressionYeast and Fungal ModelsArtificial Gene Amplification and ExtensionQH426-470BiochemistryPolymerase Chain ReactionChromosome conformation captureHistonesCromatina0302 clinical medicineSirtuin 2Macromolecular Structure AnalysisSilent Information Regulator Proteins Saccharomyces cerevisiaeCellular Senescence:Organisms::Eukaryota::Fungi::Yeasts::Saccharomyces::Saccharomyces cerevisiae [Medical Subject Headings]0303 health sciencesChromosome BiologyEukaryota:Phenomena and Processes::Genetic Phenomena::Genetic Processes::DNA Replication [Medical Subject Headings]TelomereSubtelomere:Anatomy::Cells::Cellular Structures::Intracellular Space::Cell Nucleus::Cell Nucleus Structures::Intranuclear Space::Chromosomes::Chromosome Structures::Telomere [Medical Subject Headings]Chromatin3. Good healthChromatinCell biologyNucleic acidsTelomeres:Phenomena and Processes::Cell Physiological Phenomena::Cell Physiological Processes::Cell Cycle::Cell Division::Telomere Homeostasis [Medical Subject Headings]Experimental Organism SystemsDaño del ADNEpigeneticsResearch ArticleSenescenceDNA Replication:Chemicals and Drugs::Enzymes and Coenzymes::Enzymes::Hydrolases::Amidohydrolases::Histone Deacetylases [Medical Subject Headings]Chromosome Structure and FunctionProtein StructureSaccharomyces cerevisiae ProteinsSaccharomyces cerevisiaeBiologyResearch and Analysis MethodsHistone DeacetylasesChromosomes03 medical and health sciencesSaccharomycesModel Organisms:Chemicals and Drugs::Enzymes and Coenzymes::Enzymes::Transferases::One-Carbon Group Transferases::Methyltransferases [Medical Subject Headings]:Chemicals and Drugs::Amino Acids Peptides and Proteins::Proteins::Intracellular Signaling Peptides and Proteins::Sirtuins::Sirtuin 2 [Medical Subject Headings]:Chemicals and Drugs::Amino Acids Peptides and Proteins::Proteins::Fungal Proteins::Saccharomyces cerevisiae Proteins::Silent Information Regulator Proteins Saccharomyces cerevisiae [Medical Subject Headings]DNA-binding proteinsGenetics:Chemicals and Drugs::Enzymes and Coenzymes::Enzymes::Recombinases::Rec A Recombinases::Rad51 Recombinase [Medical Subject Headings]Molecular Biology TechniquesMolecular Biology030304 developmental biologyCromosomasSenescencia celularOrganismsFungiBiology and Life SciencesProteinsTelomere HomeostasisCell BiologyDNAMethyltransferasesG2-M DNA damage checkpointProteína recombinante y reparadora de ADN Rad52YeastTelomereRad52 DNA Repair and Recombination ProteinRepressor ProteinsAnimal Studies:Chemicals and Drugs::Amino Acids Peptides and Proteins::Proteins::Transcription Factors::Repressor Proteins [Medical Subject Headings]DNA damageRad51 RecombinaseHomologous recombination030217 neurology & neurosurgeryTelómeroDNA DamagePLoS Genetics
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The designer cytokine hyper-interleukin-6 is a potent activator of STAT3-dependent gene transcription in vivo and in vitro.

1999

Interleukin-6 (IL-6) triggers pivotal pathways in vivo. The designer protein hyper-IL-6 (H-IL-6) fuses the soluble IL-6 receptor (sIL-6R) through an intermediate linker with IL-6. The intracellular pathways that are triggered by H-IL-6 are not defined yet. Therefore, we studied the molecular mechanisms leading to H-IL-6-dependent gene activation. H-IL-6 stimulates haptoglobin mRNA expression in HepG2 cells, which is transcriptionally mediated as assessed by run-off experiments. The increase in haptoglobin gene transcription correlates with higher nuclear translocation of tyrosine-phosphorylated STAT3 and its DNA binding. As H-IL-6 stimulates STAT3-dependent gene transcription, we compared t…

Therapeutic gene modulationSTAT3 Transcription FactorTranscriptional ActivationTranscription GeneticRecombinant Fusion ProteinsResponse elementE-boxBiologyTransfectionBiochemistryCell LineMiceSp3 transcription factorAntigens CDCytokine Receptor gp130E2F1AnimalsHumansRNA MessengerPhosphorylationMolecular BiologyCell NucleusATF3Sp1 transcription factorMice Inbred C3HMembrane GlycoproteinsHaptoglobinsInterleukin-6Liver receptor homolog-1Biological TransportCell BiologyDNAReceptors InterleukinMolecular biologyReceptors Interleukin-6DNA-Binding ProteinsGene Expression RegulationTrans-ActivatorsTyrosineThe Journal of biological chemistry
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Glucosylation of Rho proteins by Clostridium difficile toxin B.

1995

TOXIN A and B, the major virulence factors of Clostridium difficile, are the causative agents of antibiotic-associated pseudomembran-ous colitis. In cultured cell lines their potent cytotoxicity results from their ability to induce disaggregation of the microfilament cytoskeleton1,2. Toxin B acts on the low-molecular-mass GTPase Rho A3,4, which is involved in the regulation of the actin cytoskeleton. We report here that toxin B catalyses the incorporation of up to one mole of glucose per mole of RhoA at the amino acid thre-onine at position 37. The modification was identified and localized by tandem electrospray mass spectrometry. UDP-glucose selectively serves as cosubstrate for the monogl…

ThreonineRHOAGlycosylationBacterial ToxinsMolecular Sequence DataClostridium difficile toxin AClostridium difficile toxin Bmacromolecular substancesmedicine.disease_causeMicrofilamentCatalysisMass SpectrometryGTP PhosphohydrolasesBacterial ProteinsGTP-Binding ProteinsmedicineTumor Cells CulturedAnimalsAmino Acid SequenceCytoskeletonActinCells CulturedCytoskeletonMultidisciplinarybiologyToxinClostridioides difficileActin cytoskeletonActinsRecombinant ProteinsRatsGlucoseMarsupialiaBiochemistryGlucosyltransferasesbiology.proteinrhoA GTP-Binding ProteinNature
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Ras, Rap, and Rac Small GTP-binding Proteins Are Targets for Clostridium sordellii Lethal Toxin Glucosylation

1996

Lethal toxin (LT) from Clostridium sordellii is one of the high molecular mass clostridial cytotoxins. On cultured cells, it causes a rounding of cell bodies and a disruption of actin stress fibers. We demonstrate that LT is a glucosyltransferase that uses UDP-Glc as a cofactor to covalently modify 21-kDa proteins both in vitro and in vivo. LT glucosylates Ras, Rap, and Rac. In Ras, threonine at position 35 was identified as the target amino acid glucosylated by LT. Other related members of the Ras GTPase superfamily, including RhoA, Cdc42, and Rab6, were not modified by LT. Incubation of serum-starved Swiss 3T3 cells with LT prevents the epidermal growth factor-induced phosphorylation of m…

ThreonineUridine Diphosphate GlucoseRHOABacterial ToxinsMolecular Sequence DataClostridium sordelliimacromolecular substancesCDC42GTPaseBiologyCell morphologyBiochemistryGTP PhosphohydrolasesProto-Oncogene Proteins p21(ras)MiceGTP-binding protein regulatorsGTP-Binding ProteinsAnimalsHumansAmino Acid SequenceMolecular BiologyClostridiumEpidermal Growth FactorKinase3T3 CellsCell Biologybiology.organism_classificationMolecular biologyActinsrac GTP-Binding ProteinsActin CytoskeletonKineticsGlucoserap GTP-Binding ProteinsGlucosyltransferasesCalcium-Calmodulin-Dependent Protein Kinasesbiology.proteinPhosphorylationGuanosine TriphosphateHeLa CellsJournal of Biological Chemistry
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NG2 regulates directional migration of oligodendrocyte precursor cells via Rho GTPases and polarity complex proteins.

2013

The transmembrane proteoglycan NG2 is expressed by oligodendrocyte precursor cells (OPC), which migrate to axons during developmental myelination and remyelinate in the adult after migration to injured sites. Highly invasive glial tumors also express NG2. Despite the fact that NG2 has been implicated in control of OPC migration, its mode of action remains unknown. Here, we show in vitro and in vivo that NG2 controls migration of OPC through the regulation of cell polarity. In stab wounds in adult mice we show that NG2 controls orientation of OPC toward the wound. NG2 stimulates RhoA activity at the cell periphery via the MUPP1/Syx1 signaling pathway, which favors the bipolar shape of migrat…

Threoninerho GTP-Binding ProteinsRHOAPolarity (physics)CellNerve Tissue ProteinsGTPaseBiologyCell MovementAucun;physiologyCell polaritymedicineGuanine Nucleotide Exchange FactorsHumansT-Lymphoma Invasion and Metastasis-inducing Protein 1genetics;physiologyAntigensPhosphorylationCell ShapeTight Junction ProteinsGeneral NeuroscienceChemotaxisStem CellsCell PolarityArticlesTransmembrane proteinCell biologyrac GTP-Binding ProteinsOligodendrogliamedicine.anatomical_structurenervous systembiosynthesis;geneticsphysiologybiology.proteinPhosphorylationRNAProteoglycansRNA InterferenceSignal transductionmetabolismSignal Transduction
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The actin-based motility of intracellularListeria monocytogenesis not controlled by small GTP-binding proteins of the Rho- and Ras-subfamilies

1999

In this study, we analyzed whether the actin-based motility of intracellular Listeria monocytogenes is controlled by the small GTP-binding proteins of the Rho- and Ras-subfamilies. These signalling proteins are key regulatory elements in the control of actin dynamics and their activity is essential for the maintenance of most cellular microfilament structures. We used the Clostridium difficile toxins TcdB-10463 and TcdB-1470 to specifically inactivate these GTP-binding proteins. Treatment of eukaryotic cells with either of these toxins led to a dramatic breakdown of the normal actin cytoskeleton, but did not abrogate the invasion of epithelial cells by L. monocytogenes and had no effect on …

Time FactorsArp2/3 complexClostridium difficile toxin Bmacromolecular substancesBiologyMicrofilamentMicrobiologyCell LineBacterial ProteinsGTP-Binding ProteinsGeneticsMolecular BiologyMicroscopy ConfocalMicroscopy VideoClostridioides difficileActin remodelingActin cytoskeletonListeria monocytogenesActinsCell biologyEndotoxinsProfilinParacytophagyMicroscopy Electron Scanningras Proteinsbiology.proteinMDia1FEMS Microbiology Letters
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Function of DcuS from Escherichia coli as a Fumarate-stimulated Histidine Protein Kinase in Vitro

2002

The two-component regulatory system DcuSR of Escherichia coli controls the expression of genes of C(4)-dicarboxylate metabolism in response to extracellular C(4)- dicarboxylates such as fumarate or succinate. DcuS is a membrane-integral sensor kinase, and the sensory and kinase domains are located on opposite sides of the cytoplasmic membrane. The intact DcuS protein (His(6)-DcuS) was overproduced and isolated in detergent containing buffer. His(6)-DcuS was reconstituted into liposomes made from E. coli phospholipids. Reconstituted His(6)-DcuS catalyzed, in contrast to the detergent-solubilized sensor, autophosphorylation by [gamma-(33)P]ATP with an approximate K(D) of 0.16 mm for ATP. Up t…

Time FactorsHistidine KinaseProteolipidsDetergentsBiologymedicine.disease_causeModels BiologicalBiochemistryAdenosine TriphosphateFumaratesEscherichia colimedicinePhosphorylationPromoter Regions GeneticProtein kinase AMolecular BiologyEscherichia coliDose-Response Relationship DrugKinaseEscherichia coli ProteinsCell MembraneAutophosphorylationDNACell BiologyTransmembrane proteinDNA-Binding ProteinsKineticsResponse regulatorBiochemistryLiposomesPhosphorylationSignal transductionProtein KinasesProtein BindingSignal TransductionTranscription FactorsJournal of Biological Chemistry
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