Searching the Resource Information Network

Our searching services are busy right now. Please try again later

  • Register
X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

X

Leaving Community

Are you sure you want to leave this community? Leaving the community will revoke any permissions you have been granted in this community.

No
Yes

This service exclusively searches for literature that cites resources. Please be aware that the total number of searchable documents is limited to those containing RRIDs and does not include all open-access literature.

Search

Type in a keyword to search

On page 18 showing 341 ~ 360 papers out of 72,863 papers

Strategy for the creation of clinical grade hESC line banks that HLA-match a target population.

  • Laureen Jacquet‎ et al.
  • EMBO molecular medicine‎
  • 2013‎

Here, we describe a pre-derivation embryo haplotyping strategy that we developed in order to maximize the efficiency and minimize the costs of establishing banks of clinical grade hESC lines in which human leukocyte antigen (HLA) haplotypes match a significant proportion of the population. Using whole genome amplification followed by medium resolution HLA typing using PCR amplification with sequence-specific primers (PCR-SSP), we have typed the parents, embryos and hESC lines from three families as well as our eight clinical grade hESC lines and shown that this technical approach is rapid, reliable and accurate. By employing this pre-derivation strategy where, based on HLA match, embryos are selected for a GMP route on day 3-4 of development, we would have drastically reduced our cGMP laboratory running costs.


Scaffolding low quality genomes using orthologous protein sequences.

  • Yang I Li‎ et al.
  • Bioinformatics (Oxford, England)‎
  • 2013‎

The ready availability of next-generation sequencing has led to a situation where it is easy to produce very fragmentary genome assemblies. We present a pipeline, SWiPS (Scaffolding With Protein Sequences), that uses orthologous proteins to improve low quality genome assemblies. The protein sequences are used as guides to scaffold existing contigs, while simultaneously allowing the gene structure to be predicted by homology.


The coactivator role of histone deacetylase 3 in IL-1-signaling involves deacetylation of p65 NF-κB.

  • Elisabeth Ziesché‎ et al.
  • Nucleic acids research‎
  • 2013‎

Histone deacetylase (HDAC) 3, as a cofactor in co-repressor complexes containing silencing mediator for retinoid or thyroid-hormone receptors (SMRT) and nuclear receptor co-repressor (N-CoR), has been shown to repress gene transcription in a variety of contexts. Here, we reveal a novel role for HDAC3 as a positive regulator of IL-1-induced gene expression. Various experimental approaches involving RNAi-mediated knockdown, conditional gene deletion or small molecule inhibitors indicate a positive role of HDAC3 for transcription of the majority of IL-1-induced human or murine genes. This effect was independent from the gene regulatory effects mediated by the broad-spectrum HDAC inhibitor trichostatin A (TSA) and thus suggests IL-1-specific functions for HDAC3. The stimulatory function of HDAC3 for inflammatory gene expression involves a mechanism that uses binding to NF-κB p65 and its deacetylation at various lysines. NF-κB p65-deficient cells stably reconstituted to express acetylation mimicking forms of p65 (p65 K/Q) had largely lost their potential to stimulate IL-1-triggered gene expression, implying that the co-activating property of HDAC3 involves the removal of inhibitory NF-κB p65 acetylations at K122, 123, 314 and 315. These data describe a novel function for HDAC3 as a co-activator in inflammatory signaling pathways and help to explain the anti-inflammatory effects frequently observed for HDAC inhibitors in (pre)clinical use.


N-Acyl amines of docosahexaenoic acid and other n-3 polyunsatured fatty acids - from fishy endocannabinoids to potential leads.

  • Jocelijn Meijerink‎ et al.
  • British journal of pharmacology‎
  • 2013‎

N-3 Long-chain polyunsaturated fatty acids (n-3 LC-PUFAs), in particular α-linolenic acid (18:3n-3), eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) are receiving much attention because of their presumed beneficial health effects. To explain these, a variety of mechanisms have been proposed, but their interactions with the endocannabinoid system have received relatively little attention so far. However, it has already been shown some time ago that consumption of n-3 LC-PUFAs not only affects the synthesis of prototypic endocannabinoids like anandamide but also stimulates the formation of specific n-3 LC-PUFA-derived conjugates with ethanolamine, dopamine, serotonin or other amines. Some of these fatty amides show overlapping biological activities with those of typical endocannabinoids, whereas others possess distinct and sometimes largely unknown receptor affinities and other properties. The ethanolamine and dopamine conjugates of DHA have been the most investigated thus far. These mediators may provide promising new leads to the field of inflammatory and neurological disorders and for other pharmacological applications, including their use as carrier molecules for neurotransmitters to target the brain. Furthermore, combinations of n-3 LC-PUFA-derived fatty acid amides, their precursors and FAAH inhibitors offer possibilities to optimise their effects in health and disease.


Attenuated stress-evoked anxiety, increased sucrose preference and delayed spatial learning in glucocorticoid-induced receptor-deficient mice.

  • L E Vollmer‎ et al.
  • Genes, brain, and behavior‎
  • 2013‎

The glucocorticoid-induced receptor (GIR) is a stress-responsive gene that is abundantly expressed in forebrain limbic regions. Glucocorticoid-induced receptor has been classified as a Neuropeptide Y-like receptor, however, physiological attributes have not been investigated. In this study, mice lacking GIR (-/-) were screened in various paradigms related to stress, anxiety, activity, memory, fear and reward. GIR -/- mice elicited behavioral insensitivity to the anxiogenic effects of restraint stress. However, hypothalamic pituitary adrenal axis response to stress was not impacted by GIR deficiency. Increased preference for sucrose was observed in GIR -/- mice suggestive of modulation of reward-associated behaviors by the receptor. A delayed acquisition of spatial learning was also observed in GIR -/- mice. There were no effects of genotype on the modulation of anxiety-like behavior, activity, fear-conditioning and extinction. Our data extend previous studies on GIR regulation by glucocorticoids and provide novel evidence for a role of GIR in reward, learning and the behavioral outcomes of stress.


Orientia tsutsugamushi, the causative agent of scrub typhus, induces an inflammatory program in human macrophages.

  • Wiwit Tantibhedhyangkul‎ et al.
  • Microbial pathogenesis‎
  • 2013‎

Scrub typhus is a life-threatening disease caused by Orientia tsutsugamushi, a bacterium that primarily infects endothelial cells both in vitro and in vivo. Evidence suggests that the interaction of O. tsutsugamushi with myeloid cells may play a pivotal role in O. tsutsugamushi infection. We demonstrated that O. tsutsugamushi replicated within human monocyte-derived macrophages. Bacteria stimulated the expression of a large number of genes, including type I interferon genes, interferon-stimulated genes, inflammation-associated genes and apoptosis-related genes, and the release of inflammatory cytokines such as Tumor Necrosis Factor and interleukin-1β. In addition, O. tsutsugamushi induced an M1-type genetic program in macrophages. O. tsutsugamushi viability was required for the type I interferon response and, to a lesser degree, for the inflammatory response. As interferon-γ is known to elicit M1 polarization, we assessed the effect of interferon-γ on the fate of O. tsutsugamushi in macrophages. Exogenous interferon-γ partially inhibited O. tsutsugamushi replication within macrophages. Our results suggest that the inflammatory response induced by O. tsutsugamushi may account for the local and systemic inflammation observed in scrub typhus.


An iTRAQ-based mitoproteomics approach for profiling the nephrotoxicity mechanisms of ochratoxin A in HEK 293 cells.

  • Xiao Li Shen‎ et al.
  • Journal of proteomics‎
  • 2013‎

Nephrotoxicity is the most prominent of ochratoxin A (OTA) among the diverse range of toxicological effects. Previous work indicated that reactive oxygen species (ROS) play an important role in the pathogenesis of a variety of renal diseases, and its major endogenous source is mitochondria. No research has used global protein expression profiling to investigate potential toxicity mechanisms of OTA at the mitochondria level. An iTRAQ-based mitoproteomics approach was used to explore possible toxicity mechanisms of OTA and potential protective mechanisms of N-acetyl-L-cysteine (NAC) using the mitochondria of Human Embryonic Kidney 293 (HEK 293) cells. Our results showed that OTA induced a decrease in ΔΨm, and an increase in ROS and cell death. We identified a total of 1973 nonredundant proteins, among which 1398 proteins (70.86%) were overlapped. There were 66 significantly different proteins expressed in response to OTA, which were mainly involved in the perturbation of the mitochondrial electron transport chain (mETC), inhibition of protein synthesis, and induction of stress response and cell death. In addition, NAC could almost completely reverse the adverse effects of OTA at the protein level. Finally, a hypothetical model of OTA-induced mitochondria damage is proposed to provide a framework for the toxicity mechanism of OTA.


Mitochondrial-associated nitric oxide synthase activity inhibits cytochrome c oxidase: implications for breast cancer.

  • Suvajit Sen‎ et al.
  • Free radical biology & medicine‎
  • 2013‎

Nitric oxide (NO) is produced and nitric oxide synthase (NOS) activity is expressed in many types of tumor cells, but their precise role in tumor proliferation has not been clearly elucidated. Recently, it has been observed that patients with triple-negative breast tumors expressing NOS have a significantly worse prognosis compared to those that do not express any NOS. We observed that NOS activity was associated with the mitochondria in two breast cancer cell lines, ZR-75-30 and BT-474, compared with another NO-producing benign breast epithelial cell line, MCF-12F, in which no significant mitochondrial-associated NOS activity was detected. The rate of proliferation of the malignant cells expressing mitochondrial-associated NOS was decreased in the presence of an inhibitor of NO synthesis, but it had no effect on the normal breast epithelial cells, MCF-12F, which also expressed NOS, but not associated with mitochondria. The basal rate of proliferation was not affected by ODQ, an inhibitor of soluble guanylate cyclase, indicating that the effects of the endogenous NO produced by the malignant cell lines on proliferation are cGMP independent. Our results indicate that mitochondrial-associated NOS activity exhibited by the cancer cell lines ZR-75-30 and BT-474 inhibited cytochrome c oxidase, resulting in increased production of hydrogen peroxide (H2O2), which inhibited protein phosphatase 2A activity. This resulted in the maintenance of Akt and ERK1/2 in a phosphorylated state, leading to cell proliferation.


Lack of huntingtin promotes neural stem cells differentiation into glial cells while neurons expressing huntingtin with expanded polyglutamine tracts undergo cell death.

  • Paola Conforti‎ et al.
  • Neurobiology of disease‎
  • 2013‎

Huntington's disease (HD) is a neurodegenerative disorder that affects muscle coordination and diminishes cognitive abilities. The genetic basis of the disease is an expansion of CAG repeats in the Huntingtin (Htt) gene. Here we aimed to generate a series of mouse neural stem (NS) cell lines that carried varying numbers of CAG repeats in the mouse Htt gene (Hdh CAG knock-in NS cells) or that had Hdh null alleles (Hdh knock-out NS cells). Towards this end, Hdh CAG knock-in mouse ES cell lines that carried an Htt gene with 20, 50, 111, or 140 CAG repeats or that were Htt null were neuralized and converted into self-renewing NS cells. The resulting NS cell lines were immunopositive for the neural stem cell markers NESTIN, SOX2, and BLBP and had similar proliferative rates and cell cycle distributions. After 14 days in vitro, wild-type NS cells gave rise to cultures composed of 70% MAP2(+) neurons and 30% GFAP(+) astrocytes. In contrast, NS cells with expanded CAG repeats underwent neuronal cell death, with only 38%±15% of the MAP2(+) cells remaining at the end of the differentiation period. Cell death was verified by increased caspase 3/7 activity on day 14 of the neuronal differentiation protocol. Interestingly, Hdh knock-out NS cells treated using the same neuronal differentiation protocol showed a dramatic increase in the number of GFAP(+) cells on day 14 (61%±20% versus 24%±10% in controls), and a massive decrease of MAP2(+) neurons (30%±11% versus 64%±17% in controls). Both Hdh CAG knock-in NS cells and Hdh knock-out NS cells showed reduced levels of Bdnf mRNA during neuronal differentiation, in agreement with data obtained previously in HD mouse models and in post-mortem brain samples from HD patients. We concluded that Hdh CAG knock-in and Hdh knock-out NS cells have potential as tools for investigating the roles of normal and mutant HTT in differentiated neurons and glial cells of the brain.


Establishment of a rapid and scalable gene expression system in livestock by site-specific integration.

  • Huiqing Yu‎ et al.
  • Gene‎
  • 2013‎

Somatic cell-mediated transgenesis is routinely used to transfer exogenous genes to livestock genomes. However, transgene insertion events are essentially random which may lead to transgene silencing or alter animal phenotype because of insertional mutagenesis. To overcome these problems, we established a gene manipulation system in goat somatic cells based on homologous recombination and flp recombinase-mediated site-specific integration. First, we performed gene targeting to introduce an frt-docking site into the α1 (I) procollagen (ColA1) locus in goat somatic cells. Second, the targeted cell clones were rejuvenated by embryo cloning, and the vigorous cells with targeted frt were reestablished. Third, a gene-replacement system was used to introduce an EGFP reporter gene into the targeted ColA1 locus via flp mediated recombination. As a result, the transgenic somatic cell exhibited faithful expression of EGFP gene under control of the CMV promoter. Similarly, other expression vectors can be introduced into the defined site to evaluate gene functions or express valuable proteins. The gene manipulation system described here will be applicable in other livestock somatic cells, and would allow for the rapid generation of livestock with transgene targeted to the defined site.


Sodium-dependent vitamin C transporter SVCT2: expression and function in bone marrow stromal cells and in osteogenesis.

  • Sadanand Fulzele‎ et al.
  • Stem cell research‎
  • 2013‎

Ascorbic acid (Vitamin C) has a critical role in bone formation and osteoblast differentiation, but very little is known about the molecular mechanisms of ascorbic acid entry into bone marrow stromal cells (BMSCs). To address this gap in knowledge, we investigated the identity of the transport system that is responsible for the uptake of ascorbic acid into bone marrow stromal cells (BMSCs). First, we examined the expression of the two known isoforms of the sodium-coupled ascorbic acid transporter, namely SVCT1 and SVCT2, in BMSCs (Lin-ve Sca1+ve) and bone at the mRNA level. Only SVCT2 mRNA was detected in BMSCs and bone. Uptake of ascorbic acid in BMSCs was Na(+)-dependent and saturable. In order to define the role of SVCT2 in BMSC differentiation into osteoblasts, BMSCs were stimulated with osteogenic media for different time intervals, and the activity of SVCT2 was monitored by ascorbic acid uptake. SVCT2 expression was up-regulated during the osteogenic differentiation of BMSCs; the expression was maximal at the earliest phase of differentiation. Subsequently, osteogenesis was inhibited in BMSCs upon knock-down of SVCT2 by lentivirus shRNA. We also found that the expression of the SVCT2 could be negatively or positively modulated by the presence of oxidant (Sin-1) or antioxidant (Ascorbic acid) compounds, respectively, in BMSCs. Furthermore, we found that this transporter is also regulated with age in mouse bone. These data show that SVCT2 plays a vital role in the osteogenic differentiation of BMSCs and that its expression is altered under conditions associated with redox reaction. Our findings could be relevant to bone tissue engineering and bone related diseases such as osteoporosis in which oxidative stress and aging plays important role.


Transient removal of CD46 is safe and increases B-cell depletion by rituximab in CD46 transgenic mice and macaques.

  • Ines Beyer‎ et al.
  • Molecular therapy : the journal of the American Society of Gene Therapy‎
  • 2013‎

We have developed a technology that depletes the complement regulatory protein (CRP) CD46 from the cell surface, and thereby sensitizes tumor cells to complement-dependent cytotoxicity triggered by therapeutic monoclonal antibodies (mAbs). This technology is based on a small recombinant protein, Ad35K++, which induces the internalization and subsequent degradation of CD46. In preliminary studies, we had demonstrated the utility of the combination of Ad35K++ and several commercially available mAbs such as rituximab, alemtuzumab, and trastuzumab in enhancing cell killing in vitro as well as in vivo in murine xenograft and syngeneic tumor models. We have completed scaled manufacturing of Ad35K++ protein in Escherichia coli for studies in nonhuman primates (NHPs). In macaques, we first defined a dose of the CD20-targeting mAb rituximab that did not deplete CD20-positive peripheral blood cells. Using this dose of rituximab, we then demonstrated that pretreatment with Ad35K++ reconstituted near complete elimination of B cells. Further studies demonstrated that the treatment was well tolerated and safe. These findings in a relevant large animal model provide the rationale for moving this therapy forward into clinical trials in patients with CD20-positive B-cell malignancies.


Astrocytic GABA transporter GAT-1 dysfunction in experimental absence seizures.

  • Tiina Pirttimaki‎ et al.
  • The Journal of physiology‎
  • 2013‎

An enhanced tonic GABA(A) inhibition in the thalamus plays a crucial role in experimental absence seizures and has been attributed, on the basis of indirect evidence, to a dysfunction of the astrocytic GABA transporter-1 (GAT-1). Here, the GABA transporter current was directly investigated in thalamic astrocytes from a well-established genetic model of absence seizures, the genetic absence epilepsy rats from Strasbourg (GAERS), and its non-epileptic control (NEC) strain. We also characterized the novel form of GABAergic and glutamatergic astrocyte-to-neuron signalling by recording slow outward currents (SOCs) and slow inward currents (SICs), respectively, in thalamocortical (TC) neurons of both strains. In patch-clamped astrocytes, the GABA transporter current was abolished by combined application of the selective GAT-1 and GAT-3 blocker, NO711 (30 μm) and SNAP5114 (60 μm), respectively, to GAERS and NEC thalamic slices. NO711 alone significantly reduced (41%) the transporter current in NEC, but had no effect in GAERS. SNAP5114 alone reduced by half the GABA transporter current in NEC, whilst it abolished it in GAERS. SIC properties did not differ between GAERS and NEC TC neurons, whilst moderate changes in SOC amplitude and kinetics were observed. These data provide the first direct demonstration of a malfunction of the astrocytic thalamic GAT-1 transporter in absence epilepsy and support an abnormal astrocytic modulation of thalamic ambient GABA levels. Moreover, while the glutamatergic astrocyte-neuron signalling is unaltered in the GAERS thalamus, the changes in some properties of the GABAergic astrocyte-neuron signalling in this epileptic strain may contribute to the generation of absence seizures.


In vitro and in vivo studies on radiobiological effects of prolonged fraction delivery time in A549 cells.

  • Ling Jiang‎ et al.
  • Journal of radiation research‎
  • 2013‎

Intensity-modulated radiation therapy, when used in the clinic, prolongs fraction delivery time. Here we investigated both the in vivoand in vitroradiobiological effects on the A549 cell line, including the effect of different delivery times with the same dose on A549 tumor growth in nude mice. The in vitroeffects were studied with clonogenic assays, using linear-quadratic and incomplete repair models to fit the dose-survival curves. Fractionated irradiation of different doses was given at one fraction per day, simulating a clinical dose-time-fractionation pattern. The longer the interval between the exposures, the more cells survived. To investigate the in vivoeffect, we used sixty-four nude mice implanted with A549 cells in the back legs, randomly assigned into eight groups. A 15 Gy radiation dose was divided into different subfractions. The maximum and minimum tumor diameters were recorded to determine tumor growth. Tumor growth was delayed for groups with prolonged delivery time (40 min) compared to the group receiving a single dose of 15 Gy (P< 0.05), and tumors with a 20 min delivery time had delayed growth compared to those with a 40 min delivery time [20' (7.5 Gy × 2 F) vs 40' (7.5 Gy × 2 F), P= 0.035; 20' (3 Gy × 5 F) vs 40' (3 Gy × 5 F); P= 0.054; 20' (1.67 Gy × 9 F) vs 40' (1.67 Gy × 9 F), P= 0.028]. A prolonged delivery time decreased the radiobiological effects, so we strongly recommend keeping the delivery time as short as possible.


Quantification of the N-glycosylated secretome by super-SILAC during breast cancer progression and in human blood samples.

  • Paul J Boersema‎ et al.
  • Molecular & cellular proteomics : MCP‎
  • 2013‎

Cells secrete a large number of proteins to communicate with their surroundings. Furthermore, plasma membrane proteins and intracellular proteins can be released into the extracellular space by regulated or non-regulated processes. Here, we profiled the supernatant of 11 cell lines that are representative of different stages of breast cancer development by specifically capturing N-glycosylated peptides using the N-glyco FASP technology. For accurate quantification we developed a super-SILAC mix from several labeled breast cancer cell lines and used it as an internal standard for all samples. In total, 1398 unique N-glycosylation sites were identified and quantified. Enriching for N-glycosylated peptides focused the analysis on classically secreted and membrane proteins. N-glycosylated secretome profiles correctly clustered the different cell lines to their respective cancer stage, suggesting that biologically relevant differences were detected. Five different profiles of glycoprotein dynamics during cancer development were detected, and they contained several proteins with known roles in breast cancer. We then used the super-SILAC mix in plasma, which led to the quantification of a large number of the previously identified N-glycopeptides in this important body fluid. The combination of quantifying the secretome of cancer cell lines and of human plasma with a super-SILAC approach appears to be a promising new approach for finding markers of disease.


Myocardial tissue engineering and heart muscle repair.

  • Bijoy Chandapillai Karikkineth‎ et al.
  • Current pharmaceutical biotechnology‎
  • 2013‎

Cardiovascular diseases, including myocardial infarction and heart failure, are the main causes of death worldwide. Classical pharmacological treatment may halt, but cannot reverse the underlying disease process. Cellular cardiomyoplasty has the potential to reconstruct myocardium in situ; yet, it is hampered by poor cell survival, engraftment, and differentiation. Tissue engineering has emerged as an alternative cell-based approach, aiming at partial or full replacement of damaged organs with in vitro generated tissue equivalents. However, limited availability of therapeutic cardiomyocytes poses a major challenge on cell-based and in particular tissue engineering-based therapies. Rapidly evolving stem cell technologies, enabling mass cultures may overcome this limitation. Translating available experimental concepts into clinical reality will be the ultimate challenge. This review discusses potentially therapeutic cells for cardiac repair, current stem cell-based myocardial tissue engineering strategies, and the requirements for a translation of myocardial tissue engineering into clinical practice.


Value of endovascular stent placement for symptomatic spontaneous isolated superior mesenteric artery dissection.

  • Pengfei Pang‎ et al.
  • European journal of radiology‎
  • 2013‎

To evaluate the feasibility and efficacy of endovascular stent placement for the treatment of symptomatic spontaneous isolated superior mesenteric artery dissection.


The benign spectrum of hypothalamic hamartomas: infrequent epilepsy and normal cognition in patients presenting with central precocious puberty.

  • Priscilla Cukier‎ et al.
  • Seizure‎
  • 2013‎

Hypothalamic hamartoma (HH) is the main structural cause of central precocious puberty (CPP). HH is frequently associated with cognitive impairment and epileptic encephalopathies. Disease severity in case series from neurology services may be biased towards more neurologically impaired patients.


Characterization of LIC11207, a novel leptospiral protein that is recognized by human convalescent sera and prevents apoptosis of polymorphonuclear leukocytes.

  • Gabriela Pretre‎ et al.
  • Microbial pathogenesis‎
  • 2013‎

We report the study of a predicted outer-membrane leptospiral protein encoded by the gene lic11207. This protein is conserved in several pathogenic leptospiral strains but is absent in the saprophyte Leptospira biflexa. This putative outer-membrane protein has a domain of unknown function (DUF) 1565 found in several phylogenetically diverse bacteria and in the archaeon Methanosarcina acetivorans. The gene was cloned and expressed in Escherichia coli BL21 (SI) strain using the expression vector pDEST17. The 34 kDa recombinant protein was tagged with N-terminal hexahistidine and purified by metal-charged chromatography. The purified protein was used to assess: reactivity with human convalescent sera; in vivo expression; ability to activate endothelial cells (EC); and ability to modulate the apoptosis of polymorphonuclear cells (PMNs). The LIC11207 coding sequence was identified in vivo in the hamster renal tubules during experimental infection with Leptospira interrogans. The rLIC11207 showed significant antigenicity against human convalescent sera when compared with sera from healthy donors. The recombinant protein did not alter the surface expression of E-selectin or intercellular adhesion molecule 1 (ICAM-1) in EC and failed to induce the release of von Willebrand factor (vWF). Interestingly, rLIC11207 delayed apoptosis of PMNs suggesting a possible role of this protein during the infection.


Dissociation and re-association of RNA polymerase with DNA during osmotic stress response in Escherichia coli.

  • Cedric Cagliero‎ et al.
  • Nucleic acids research‎
  • 2013‎

The thermodynamic association of RNA polymerase (RNAP) with DNA is sensitive to salt concentration in vitro. Paradoxically, previous studies of changes in osmolarity during steady-state cell growth found no dependence between the association of RNAP to DNA and K(+) concentration in Escherichia coli. We reevaluated this issue by following the interaction of RNAP and genomic DNA in time-course experiments during the hyper-osmotic response. Our results show that the interaction is temporally controlled by the same physical chemistry principle in the cell as in vitro. RNAP rapidly dissociates from the genome during the initial response when the cytoplasmic K(+) accumulates transiently, and concurrently the nucleoid becomes hyper-condensed. The freed RNAP re-associates with the genome during a subsequent osmoadaptation phase when organic osmoprotectants accumulate as K(+) levels decrease. RNAP first surrounds the hyper-condensed nucleoid forming a sphere of RNAP before it progressively moves in to the center of the nucleoid. Our findings reinterpret the dynamic protein-DNA interactions during osmotic stress response. We discuss the implications of the dissociation/association of RNAP for osmotic protection and nucleoid structure.


  1. SPARC Anatomical Working Group Resources

    Welcome to the SPARC SAWG Resources search. From here you can search through a compilation of resources used by SPARC SAWG and see how data is organized within our community.

  2. Navigation

    You are currently on the Community Resources tab looking through categories and sources that SPARC SAWG has compiled. You can navigate through those categories from here or change to a different tab to execute your search through. Each tab gives a different perspective on data.

  3. Logging in and Registering

    If you have an account on SPARC SAWG then you can log in from here to get additional features in SPARC SAWG such as Collections, Saved Searches, and managing Resources.

  4. Searching

    Here is the search term that is being executed, you can type in anything you want to search for. Some tips to help searching:

    1. Use quotes around phrases you want to match exactly
    2. You can manually AND and OR terms to change how we search between words
    3. You can add "-" to terms to make sure no results return with that term in them (ex. Cerebellum -CA1)
    4. You can add "+" to terms to require they be in the data
    5. Using autocomplete specifies which branch of our semantics you with to search and can help refine your search
  5. Save Your Search

    You can save any searches you perform for quick access to later from here.

  6. Query Expansion

    We recognized your search term and included synonyms and inferred terms along side your term to help get the data you are looking for.

  7. Collections

    If you are logged into SPARC SAWG you can add data records to your collections to create custom spreadsheets across multiple sources of data.

  8. Facets

    Here are the facets that you can filter your papers by.

  9. Options

    From here we'll present any options for the literature, such as exporting your current results.

  10. Further Questions

    If you have any further questions please check out our FAQs Page to ask questions and see our tutorials. Click this button to view this tutorial again.

Publications Per Year

X

Year:

Count: