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1.
J.D. Kibble S.L. Greenwood L.H. Clarson C.P. Sibley 《The Journal of membrane biology》1996,151(2):131-138
Whole-cell patch clamp experiments were performed on cultured human cytotrophoblast cells incubated for 24–48 hr after their
isolation from term placentas. Cl−-selective currents were examined using K+-free solutions. Under nonstimulated conditions, most cells initially expressed only small background leak currents. However,
inclusion of 0.2 mm GTPγS in the electrode solution caused activation of an outwardly rectifying conductance which showed marked time-dependent
activation at depolarized potentials above +20 mV. Stimulation of this conductance by GTPγS was found to be Ca2+-dependent since GTPγS failed to activate currents when included in a Ca2+-free electrode solution. In addition, similar currents could be activated by increasing the [Ca2+] of the pipette solution to 500 nm. The Ca2+-activated conductance was judged to be Cl−-selective, since reversal potentials were predicted by Nernst equilibrium potentials for Cl−. This conductance could also be reversibly inhibited by addition of the anion channel blocker DIDS to the bath solution at
a dose of 100 μm. Preliminary experiments indicated the presence of a second whole-cell anion conductance in human cytotrophoblast cells,
which may be activated by cell swelling. Possible roles for the Ca2+-activated Cl− conductance in human placental trophoblast are discussed.
Received: 9 November 1995/Revised: 18 January 1996 相似文献
2.
Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase
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Sharon C Mithoe Christina Ludwig Michiel JC Pel Mara Cucinotta Alberto Casartelli Malick Mbengue Jan Sklenar Paul Derbyshire Silke Robatzek Corné MJ Pieterse Ruedi Aebersold Frank LH Menke 《EMBO reports》2016,17(3):441-454
Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex. 相似文献
3.
Conformation and assembly of polypeptide scaffolds in templating the synthesis of silica: an example of a polylysine macromolecular "switch" 总被引:2,自引:0,他引:2
Although the role of polycationic macromolecules in catalyzing the synthesis of silica structures is well established, detailed understanding of the mechanisms behind the production of silica structures of controlled morphologies remains unclear. In this study, we have used both poly-L-lysine (PLL) and/or poly-D-lysine (PDL) for silica synthesis to investigate mechanisms controlling inorganic morphologies. The formation of both spherical silica particles and hexagonal plates was observed. The formation of hexagonal plates was suggested, via circular dichroic spectroscopy (CD), to result from the assembly of helical polylysine molecules. We confirm that the formation of PLL helices is a prerequisite to the hexagonal silica synthesis. In addition, we present for the first time that the handedness of the helicity of the macromolecule does not affect the formation of hexagonal silica. We also show, by using two different silica precursors, that the precursor does not have a direct effect on the formation of hexagonal silica plates. Furthermore, when polylysine helices were converted to beta-sheet structure, only silica particles were obtained, thus suggesting that the adoption of a helical conformation by PLL is required for the formation of hexagonally organized silica. These results demonstrate that the change in polylysine conformation can act as a "switch" in silica structure formation and suggest the potential for controlling morphologies and structures of inorganic materials via control of the conformation of soft macromolecular templates. 相似文献
4.
Bowirrat A Chen TJ Oscar-Berman M Madigan M Chen AL Bailey JA Braverman ER Kerner M Giordano J Morse S Downs BW Waite RL Fornari F Armaly Z Blum K 《Molecular neurobiology》2012,45(2):298-313
Executive functions are processes that act in harmony to control behaviors necessary for maintaining focus and achieving outcomes. Executive dysfunction in neuropsychiatric disorders is attributed to structural or functional pathology of brain networks involving prefrontal cortex (PFC) and its connections with other brain regions. The PFC receives innervations from different neurons associated with a number of neurotransmitters, especially dopamine (DA). Here we review findings on the contribution of PFC DA to higher-order cognitive and emotional behaviors. We suggest that examination of multifactorial interactions of an individual's genetic history, along with environmental risk factors, can assist in the characterization of executive functioning for that individual. Based upon the results of genetic studies, we also propose genetic mapping as a probable diagnostic tool serving as a therapeutic adjunct for augmenting executive functioning capabilities. We conclude that preservation of the neurological underpinnings of executive functions requires the integrity of complex neural systems including the influence of specific genes and associated polymorphisms to provide adequate neurotransmission. 相似文献
5.
A. Dutour P. Giraud J. Y. Maltese D. Becquet G. Pesce P. Salers LH. Ouafik M. Renard C. Oliver 《Peptides》1990,11(6):1081-1085
The TRH secretory responsiveness of the pancreatic islet cell clusters from newborn rat in organ culture was studied. Basal TRH secretion was stable over a 9-day period. The response to various secretagogues was tested on day 4. TRH secretion was stimulated by high potassium-induced depolarization and also through both cAMP and protein kinase-C dependent pathways. Like insulin, TRH release was stimulated by glucose and arginine and inhibited by somatostatin. These data suggest the existence of a common mechanism for TRH and insulin secretion by the pancreatic β-cells. 相似文献
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7.
Attempts to eliminate Sarcoptes scabiei var. suis were made in 2 naturally infested sow herds, by intramuscular (IM) injection of doramectin (Dectomax®, Pfizer, New York, USA). A single injection strategy was used. In one of the herds, the environment was treated with an acaricide following dry cleaning of floors, walls and equipment. In the second herd, no environmental treatment was performed. Results were measured by skin lesion scoring, ear scrapings to show Sarcoptes scabiei var. suis, and calculating rubbing index throughout the observation period of 20 months following treatment. Skin lesion scores decreased and stayed low following treatment for the entire observation period. Live Sarcoptes scabiei var. suis mites were isolated prior to treatment from both herds, but not following treatment. Rubbing index decreased following treatment, but was occasionally at or above 0.4. The results of these studies indicate that elimination of Sarcoptes scabiei var. suis from 2 naturally infested herds was successful, using doramectin in a single injection strategy. Precautions must be taken to ensure adequate dosing of every pig, and to avoid reinfestation due to poor biosecurity. 相似文献
8.
Using a shore-based station we monitored the position of sperm whales (Physeter macrocephalus) within the Kaikoura submarine canyon from 2010 to 2012. We tracked sperm whales using a theodolite station for a total of 290 days. We extracted the distance from the nearest coast, the depth and the bathymetric slope using ArcGIS 10.1. We estimated the seasonal spatial distribution of sperm whales using general additive models. The distribution varied significantly between seasons; individuals were found in deeper water and further offshore in the spring than in winter. This study improved our understanding of the variability of sperm whale distribution patterns off Kaikoura. We determined that the distribution was linked to the bathymetric features and we hypothesized that whales adapted their use of the submarine canyon in relation to food aggregation. We would encourage further studies to evaluate the sperm whale relationship with oceanographic variables off Kaikoura. 相似文献
9.
Thomas Fleischer Arnoldo Frigessi Kevin C Johnson Hege Edvardsen Nizar Touleimat Jovana Klajic Margit LH Riis Vilde D Haakensen Fredrik W?rnberg Bj?rn Naume ?slaug Helland Anne-Lise B?rresen-Dale J?rg Tost Brock C Christensen Vessela N Kristensen 《Genome biology》2014,15(8)
Background
Ductal carcinoma in situ (DCIS) of the breast is a precursor of invasive breast carcinoma. DNA methylation alterations are thought to be an early event in progression of cancer, and may prove valuable as a tool in clinical decision making and for understanding neoplastic development.Results
We generate genome-wide DNA methylation profiles of 285 breast tissue samples representing progression of cancer, and validate methylation changes between normal and DCIS in an independent dataset of 15 normal and 40 DCIS samples. We also validate a prognostic signature on 583 breast cancer samples from The Cancer Genome Atlas. Our analysis reveals that DNA methylation profiles of DCIS are radically altered compared to normal breast tissue, involving more than 5,000 genes. Changes between DCIS and invasive breast carcinoma involve around 1,000 genes. In tumors, DNA methylation is associated with gene expression of almost 3,000 genes, including both negative and positive correlations. A prognostic signature based on methylation level of 18 CpGs is associated with survival of breast cancer patients with invasive tumors, as well as with survival of patients with DCIS and mixed lesions of DCIS and invasive breast carcinoma.Conclusions
This work demonstrates that changes in the epigenome occur early in the neoplastic progression, provides evidence for the possible utilization of DNA methylation-based markers of progression in the clinic, and highlights the importance of epigenetic changes in carcinogenesis.Electronic supplementary material
The online version of this article (doi:10.1186/s13059-014-0435-x) contains supplementary material, which is available to authorized users. 相似文献10.
Kim D Baas Maarten WJ Koeter Henk C van Weert Peter Lucassen Claudi LH Bockting Karin A Wittkampf Aart H Schene 《Trials》2010,11(1):1-6