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81.
Angela M. Hirtreiter Giulia Calloni Francesca Forner Burghardt Scheibe Magda Puype Joel Vandekerckhove Matthias Mann F. Ulrich Hartl Manajit Hayer‐Hartl 《Molecular microbiology》2009,74(5):1152-1168
Chaperonins are macromolecular machines that assist in protein folding. The archaeon Methanosarcina mazei has acquired numerous bacterial genes by horizontal gene transfer. As a result, both the bacterial group I chaperonin, GroEL, and the archaeal group II chaperonin, thermosome, coexist. A proteome‐wide analysis of chaperonin interactors was performed to determine the differential substrate specificity of GroEL and thermosome. At least 13% of soluble M. mazei proteins interact with chaperonins, with the two systems having partially overlapping substrate sets. Remarkably, chaperonin selectivity is independent of phylogenetic origin and is determined by distinct structural and biochemical features of proteins. GroEL prefers well‐conserved proteins with complex α/β domains. In contrast, thermosome substrates comprise a group of faster‐evolving proteins and contain a much wider range of different domain folds, including small all‐α and all‐β modules, and a greater number of large multidomain proteins. Thus, the group II chaperonins may have facilitated the evolution of the highly complex proteomes characteristic of eukaryotic cells. 相似文献
82.
Anna Stochmal Angela Perrone Sonia Piacente Wieslaw Oleszek 《Phytochemistry letters》2010,3(3):129-132
In the search of natural compounds inhibiting methane production in ruminants three novel steroidal saponins have been isolated from the aerial parts of Helleborus viridis L. Their structures have been established based on spectral analyses as: (25R)-26-O-β-d-glucopyranosyl-5β-furostan-3β,22α,26-triol 3-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside, (25R)-26-O-β-d-glucopyranosyl-5α-furostan-3β,22α,26-triol 3-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside and (25R)-26-O-β-d-glucopyranosyl-furost-5-ene-1β,3β,22α,26-tetraol 1-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 3)]-6-O-acetoxy-β-d-glucopyranoside}. 相似文献
83.
T cell activation induces CuZn superoxide dismutase (SOD)-1 intracellular re-localization,production and secretion 总被引:1,自引:0,他引:1
Giuseppe Terrazzano Valentina Rubino Simona Damiano Anna Sasso Tiziana Petrozziello Valentina Ucci Anna Teresa Palatucci Angela Giovazzino Mariarosaria Santillo Bruna De Felice Corrado Garbi Paolo Mondola Giuseppina Ruggiero 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2014
Reactive oxygen species (ROS) behave as second messengers in signal transduction for a series of receptor/ligand interactions. A major regulatory role is played by hydrogen peroxide (H2O2), more stable and able to freely diffuse through cell membranes. Copper–zinc superoxide dismutase (CuZn-SOD)-1 is a cytosolic enzyme involved in scavenging oxygen radicals to H2O2 and molecular oxygen, thus representing a major cytosolic source of peroxides. Previous studies suggested that superoxide anion and H2O2 generation are involved in T cell receptor (TCR)-dependent signaling. Here, we describe that antigen-dependent activation of human T lymphocytes significantly increased extracellular SOD-1 levels in lymphocyte cultures. This effect was accompanied by the synthesis of SOD-1-specific mRNA and by the induction of microvesicle SOD-1 secretion. It is of note that SOD-1 increased its concentration specifically in T cell population, while no significant changes were observed in the “non-T” cell counterpart. Moreover, confocal microscopy showed that antigen-dependent activation was able to modify SOD-1 intracellular localization in T cells. Indeed, was observed a clear SOD-1 recruitment by TCR clusters. The ROS scavenger N-acetylcysteine (NAC) inhibited this phenomenon. Further studies are needed to define whether SOD-1-dependent superoxide/peroxide balance is relevant for regulation of T cell activation, as well as in the functional cross talk between immune effectors. 相似文献
84.
Jeannine Günther Angela Kill Mike Oliver Becker Harald Heidecke Judith Rademacher Elise Siegert Mislav Radi? Gerd-Rüdiger Burmester Duska Dragun Gabriela Riemekasten 《Arthritis research & therapy》2014,16(2):R65
Introduction
Agonistic autoantibodies (Aabs) against the angiotensin II receptor type 1 (AT1R) and the endothelin receptor type A (ETAR) have been identified in patients with systemic sclerosis (SSc). In our present study, we examined the expression of the AT1R and the ETAR in human immune cells and the pathological effects mediated through these receptors by their corresponding Aabs.Methods
Protein expression of AT1R and ETAR on peripheral blood mononuclear cells (PBMCs) from healthy individuals and SSc patients was analyzed using flow cytometry, and mRNA expression of both receptors in PBMCs from healthy donors was examined by real-time PCR. In addition, PBMCs from healthy donors were stimulated in vitro with affinity-purified immunoglobulin G (IgG) fractions from SSc patients positive for AT1R and ETAR Aabs, as well as with IgG from healthy donors serving as controls. Alterations in cell surface marker expression, cytokine secretion and chemotactic motility were analyzed using flow cytometry, enzyme-linked immunosorbent assays and chemotaxis assays, respectively. The results were correlated with the characteristics and clinical findings of the IgG donors.Results
Both AT1R and ETAR were expressed on PBMCs in humans. Protein expression of both receptors was decreased in SSc patients compared with that of healthy donors and declined during the course of disease. IgG fractions of SSc patients positive for AT1R and ETAR Aabs induced T-cell migration in an Aab level–dependent manner. Moreover, IgG of SSc patients stimulated PBMCs to produce more interleukin 8 (IL-8) and chemokine (C-C motif) ligand 18 (CCL18) than did the IgG of healthy donors. All effects were significantly reduced by selective AT1R and ETAR antagonists. Statistical analysis revealed an association of SSc-IgG induced high IL-8 concentrations with an early disease stage and of high CCL18 concentrations with lung fibrosis onset and vascular complications in the respective IgG donors.Conclusion
In our present study, we could demonstrate the expression of both AT1R and ETAR on human peripheral T cells, B cells and monocytes. The decreased receptor expression in SSc patients, the inflammatory and profibrotic effects upon Aab stimulation of PBMCs in vitro and the associations with clinical findings suggest a role for Aab-induced activation of immune cells mediated by the AT1R and the ETAR in the pathogenesis or even the onset of the disease. 相似文献85.
Angela M. Zanata Willian M. Ohara Osvaldo T. Oyakawa Fernando C. P. Dagosta 《Journal of fish biology》2020,97(5):1343-1353
Characidium iaquira, a new species from the upper rio Juruena, rio Tapajós basin, Brazil, is described. The new species can be promptly distinguished from all congeners by having a unique v-shaped dark mark lying along the caudal-fin extension, in medium- and large-sized specimens, and a remarkable iridescent green colouration in life. Characidium iaquira is closely related to Characidium crandellii and Characidium declivirostre by sharing unambiguous synapomorphies such as branchiostegal membranes united to each other across the isthmus, a scaleless area extending from the isthmus to the pectoral girdle, and dermal flaps surrounding anterior and posterior naris independent, but touching each other distally. Morphological specializations of the paired fins in the three riffle-dwellers species are discussed, including the wing-like shape, robustness, and inclination of the pectoral fin. 相似文献
86.
Saskia von Stillfried Sophia Villwock Roman D. Bülow Sonja Djudjaj Eva M. Buhl Angela Maurer Nadina Ortiz-Brüchle Peter Celec Barbara M. Klinkhammer Dickson W.L. Wong Claudio Cacchi Till Braunschweig Ruth Knüchel-Clarke Edgar Dahl Peter Boor 《Microbial biotechnology》2021,14(4):1627-1641
Virus detection methods are important to cope with the SARS-CoV-2 pandemics. Apart from the lung, SARS-CoV-2 was detected in multiple organs in severe cases. Less is known on organ tropism in patients developing mild or no symptoms, and some of such patients might be missed in symptom-indicated swab testing. Here, we tested and validated several approaches and selected the most reliable RT-PCR protocol for the detection of SARS-CoV-2 RNA in patients’ routine diagnostic formalin-fixed and paraffin-embedded (FFPE) specimens available in pathology, to assess (i) organ tropism in samples from COVID-19-positive patients, (ii) unrecognized cases in selected tissues from negative or not-tested patients during a pandemic peak, and (iii) retrospectively, pre-pandemic lung samples. We identified SARS-CoV-2 RNA in seven samples from confirmed COVID-19 patients, in two gastric biopsies, one small bowel and one colon resection, one lung biopsy, one pleural resection and one pleural effusion specimen, while all other specimens were negative. In the pandemic peak cohort, we identified one previously unrecognized COVID-19 case in tonsillectomy samples. All pre-pandemic lung samples were negative. In conclusion, SARS-CoV-2 RNA detection in FFPE pathology specimens can potentially improve surveillance of COVID-19, allow retrospective studies, and advance our understanding of SARS-CoV-2 organ tropism and effects. 相似文献
87.
Amol A. Verma Tejasvi Hora Hae Young Jung Michael Fralick Sarah L. Malecki Lauren Lapointe-Shaw Adina Weinerman Terence Tang Janice L. Kwan Jessica J. Liu Shail Rawal Timothy C.Y. Chan Angela M. Cheung Laura C. Rosella Marzyeh Ghassemi Margaret Herridge Muhammad Mamdani Fahad Razak 《CMAJ》2021,193(23):E859
88.
Júlia R. de Rezende Thomas B. P. Oldenburg Tetyana Korin William D. L. Richardson Milovan Fustic Carolyn M. Aitken Bernard F. J. Bowler Angela Sherry Alexander Grigoryan Gerrit Voordouw Stephen R. Larter Ian M. Head Casey R. J. Hubert 《Environmental microbiology》2020,22(8):3049-3065
Most of the oil in low temperature, non-uplifted reservoirs is biodegraded due to millions of years of microbial activity, including via methanogenesis from crude oil. To evaluate stimulating additional methanogenesis in already heavily biodegraded oil reservoirs, oil sands samples were amended with nutrients and electron acceptors, but oil sands bitumen was the only organic substrate. Methane production was monitored for over 3000 days. Methanogenesis was observed in duplicate microcosms that were unamended, amended with sulfate or that were initially oxic, however methanogenesis was not observed in nitrate-amended controls. The highest rate of methane production was 0.15 μmol CH4 g−1 oil d−1, orders of magnitude lower than other reports of methanogenesis from lighter crude oils. Methanogenic Archaea and several potential syntrophic bacterial partners were detected following the incubations. GC–MS and FTICR–MS revealed no significant bitumen alteration for any specific compound or compound class, suggesting that the very slow methanogenesis observed was coupled to bitumen biodegradation in an unspecific manner. After 3000 days, methanogenic communities were amended with benzoate resulting in methanogenesis rates that were 110-fold greater. This suggests that oil-to-methane conversion is limited by the recalcitrant nature of oil sands bitumen, not the microbial communities resident in heavy oil reservoirs. 相似文献
89.
Stefano Potter Kylen Solvik Angela Erb Scott J. Goetz Jill F. Johnstone Michelle C. Mack James T. Randerson Miguel O. Romn Crystal L. Schaaf Merritt R. Turetsky Sander Veraverbeke Xanthe J. Walker Zhuosen Wang Richard Massey Brendan M. Rogers 《Global Change Biology》2020,26(3):1592-1607
Fire is a primary disturbance in boreal forests and generates both positive and negative climate forcings. The influence of fire on surface albedo is a predominantly negative forcing in boreal forests, and one of the strongest overall, due to increased snow exposure in the winter and spring months. Albedo forcings are spatially and temporally heterogeneous and depend on a variety of factors related to soils, topography, climate, land cover/vegetation type, successional dynamics, time since fire, season, and fire severity. However, how these variables interact to influence albedo is not well understood, and quantifying these relationships and predicting postfire albedo becomes increasingly important as the climate changes and management frameworks evolve to consider climate impacts. Here we developed a MODIS‐derived ‘blue sky’ albedo product and a novel machine learning modeling framework to predict fire‐driven changes in albedo under historical and future climate scenarios across boreal North America. Converted to radiative forcing (RF), we estimated that fires generate an annual mean cooling of ?1.77 ± 1.35 W/m2 from albedo under historical climate conditions (1971–2000) integrated over 70 years postfire. Increasing postfire albedo along a south–north climatic gradient was offset by a nearly opposite gradient in solar insolation, such that large‐scale spatial patterns in RF were minimal. Our models suggest that climate change will lead to decreases in mean annual postfire albedo, and hence a decreasing strength of the negative RF, a trend dominated by decreased snow cover in spring months. Considering the range of future climate scenarios and model uncertainties, we estimate that for fires burning in the current era (2016) the cooling effect from long‐term postfire albedo will be reduced by 15%–28% due to climate change. 相似文献
90.