排序方式: 共有69条查询结果,搜索用时 296 毫秒
31.
Interaction of platelets with endothelial progenitor cells in the experimental atherosclerosis: Role of transplanted endothelial progenitor cells and platelet microparticles
下载免费PDF全文
![点击此处可从《Biology of the cell / under the auspices of the European Cell Biology Organization》网站下载免费的PDF全文](/ch/ext_images/free.gif)
32.
The anaphase-promoting complex/cyclosome is required for anaphase progression in multinucleated Ashbya gossypii cells
下载免费PDF全文
![点击此处可从《Eukaryotic cell》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gladfelter AS Sustreanu N Hungerbuehler AK Voegeli S Galati V Philippsen P 《Eukaryotic cell》2007,6(2):182-197
Regulated protein degradation is essential for eukaryotic cell cycle progression. The anaphase-promoting complex/cyclosome (APC/C) is responsible for the protein destruction required for the initiation of anaphase and the exit from mitosis, including the degradation of securin and B-type cyclins. We initiated a study of the APC/C in the multinucleated, filamentous ascomycete Ashbya gossypii to understand the mechanisms underlying the asynchronous mitosis observed in these cells. These experiments were motivated by previous work which demonstrated that the mitotic cyclin AgClb1/2p persists through anaphase, suggesting that the APC/C may not be required for the division cycle in A. gossypii. We have now found that the predicted APC/C components AgCdc23p and AgDoc1p and the targeting factors AgCdc20p and AgCdh1p are essential for growth and nuclear division. Mutants lacking any of these factors arrest as germlings with nuclei blocked in mitosis. A likely substrate of the APC/C is the securin homologue AgPds1p, which is present in all nuclei in hyphae except those in anaphase. The destruction box sequence of AgPds1p is required for this timed disappearance. To investigate how the APC/C may function to degrade AgPds1p in only the subset of anaphase nuclei, we localized components and targeting subunits of the APC/C. Remarkably, AgCdc23p, AgDoc1p, and AgCdc16p were found in all nuclei in all cell cycle stages, as were the APC/C targeting factors AgCdc20p and AgCdh1p. These data suggest that the AgAPC/C may be constitutively active across the cell cycle and that proteolysis in these multinucleated cells may be regulated at the level of substrates rather than by the APC/C itself. 相似文献
33.
Rob Tinch Estelle Balian Dave Carss Driss Ezzine de Blas Nicoleta Adriana Geamana Ulrich Heink Hans Keune Carsten Nesshöver Jari Niemelä Simo Sarkki Maxime Thibon Johannes Timaeus Angheluta Vadineanu Sybille van den Hove Allan Watt Kerry A. Waylen Heidi Wittmer Juliette C. Young 《Biodiversity and Conservation》2018,27(7):1679-1702
To address the pressing problems associated with biodiversity loss, changes in awareness and behaviour are required from decision makers in all sectors. Science-policy interfaces (SPIs) have the potential to play an important role, and to achieve this effectively, there is a need to understand better the ways in which existing SPIs strive for effective communication, learning and behavioural change. Using a series of test cases across the world, we assess a range of features influencing the effectiveness of SPIs through communication and argumentation processes, engagement of actors and other aspects that contribute to potential success. Our results demonstrate the importance of dynamic and iterative processes of interaction to support effective SPI work. We stress the importance of seeing SPIs as dynamic learning environments and we provide recommendations for how they can enhance success in meeting their targeted outcomes. In particular, we recommend building long-term trust, creating learning environments, fostering participation and ownership of the process and building capacity to combat silo thinking. Processes to enable these changes may include, for example, inviting and integrating feedback, extended peer review and attention to contextualising knowledge for different audiences, and time and sustained effort dedicated to trust-building and developing common languages. However there are no ‘one size fits all’ solutions, and methods must be adapted to context and participants. Creating and maintaining effective dynamic learning environments will both require and encourage changes in institutional and individual behaviours: a challenging agenda, but one with potential for positive feedbacks to maintain momentum. 相似文献
34.
Laura Ion Catalina Ionica Ciobanu Manuela Murariu Vasile-Robert Gradinaru Gabi Drochioiu 《International journal of peptide research and therapeutics》2016,22(1):45-55
Sodium dodecyl sulfate (SDS) was introduced in polyacrylamide gel electrophoresis (PAGE) due to its capacity of helping proteins to become fully denatured and dissociated from each other. Numerous studies which have been undertaken, using electrospray ionization mass spectrometry (ESI–MS), reported on the process of peptide oligomerization. Many of these investigations have included tetraglycine (H2N–Gly–Gly–Gly–Gly–COOH; G4) as model peptide. The aim of this research is to investigate the effect of SDS on G4 oligomerization, and, especially, to emphasize the dismantling of oligomers under micellar conditions. In water, G4 peptide develops dimers and oligomers, which can also be evidenced in high proportion by MS in the gas phase. Although our results show that SDS is able to reduce the proportion of G4 oligomers, the aqueous G4-SDS system may contain G4 dimers, G4-SDS adducts alongside with the expected monomers and some alkaline metal adducts. The mechanism by which SDS disassembled G4 dimers, which includes sodium ion affinity toward negatively charged carboxyl and sulfonyl groups, was also discussed. Amyloid-β peptide1–40 conformation changed considerably and, especially, the proportion of α-helical populations increased upon SDS binding in a concentration-dependent manner. Molecular dynamics studies confirmed the tendency of Aβ molecules to form α-helical conformers, as the CD and FTIR studies showed. 相似文献
35.
Diana Nicoleta Calance Charlotte Steixner Stefanie Gross Beatrice Schuler-Thurner Gertrud Knoll Martin Ehrenschwender 《Apoptosis : an international journal on programmed cell death》2018,23(3-4):201-209
The tumor environment critically influences responsiveness of cancer cells to chemotherapies, most of which activate the mitochondria-regulated (intrinsic) apoptotic cascade to kill malignant cells. Especially skin tumors encounter an environment with remarkable biophysical properties. Cutaneous accumulation of Na+ locally establishes osmotic pressure gradients in vivo (hypertonicity or hyperosmotic stress), but whether cutaneous hypertonicity is a factor that modulates the responsiveness of skin cancers to therapeutic apoptosis-induction has thus far not been investigated. Here, we show that hyperosmotic stress lowers the threshold for apoptosis induction in malignant melanoma, the deadliest form of skin cancer. Hypertonic conditions enforce addiction to BCL-2-like proteins to prevent initiation of the mitochondria-regulated (intrinsic) apoptotic pathway. Essentially, hyperosmotic stress primes mitochondria for death. Our work identifies osmotic pressure in the tumor microenvironment as a cell extrinsic factor that modulates responsiveness of malignant melanoma cells to therapy. 相似文献
36.
The key pathogenic event in the onset of Alzheimer's disease (AD) is believed to be the aggregation of the beta-amyloid (Abeta) peptide into toxic oligomers. Molecules that interfere with this process may therefore act as therapeutic agents for the treatment of AD. N-Methylated peptides (meptides) are a general class of peptide aggregation inhibitors that act by binding to one face of the aggregating peptide but are unable to hydrogen bond on the other face, because of the N-methyl group replacing a backbone NH group. Here, we optimize the structure of meptide inhibitors of Abeta aggregation, starting with the KLVFF sequence that is known to bind to Abeta. We varied the meptide length, N-methylation sites, acetylation, and amidation of the N and C termini, side-chain identity, and chirality, via five compound libraries. Inhibitor activity was tested by thioflavin T binding, affinity chromatography, electron microscopy, and an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide toxicity assay. We found that inhibitors should have all d chirality, have a free N terminus but an amidated C terminus, and have large, branched hydrophobic side chains at positions 1-4, while the side chain at position 5 was less important. A single N-methyl group was necessary and sufficient. The most active compound, d-[(chGly)-(Tyr)-(chGly)-(chGly)-(mLeu)]-NH(2), was more active than all previously reported peptide inhibitors. Its related non-N-methylated analogues were insoluble and toxic. 相似文献
37.
Carol M. Berman Consuel S. Ionica Meredith Dorner Jinhua Li 《International journal of primatology》2006,27(3):827-854
We describe basic patterns of postconflict affiliation between former opponents within a group of wild, provisioned Tibetan macaques Macaca thibetana on Mt. Huangshan, China. Like most primates studied to date, Tibetan macaques reconciled, i.e., overall they engaged in affiliative interaction with opponents at higher rates immediately after an aggressive conflict than at other times. Probabilities of affiliation were enhanced ≤30 s after the end of hostilities. However when we examined sex partner combinations separately, we found unequivocal evidence for reconciliation only for male-male dyads. Tolerant interaction among other partner combinations apparently was not disrupted after a conflict, presumably obviating the need to reconcile. One aspect of reconciliation among males was consistent with other indications of a despotic dominance style: aggressors initiated a higher proportion of affiliative interactions after a conflict than at other times. Another aspect of reconciliation was more typical of relaxed dominance styles: males used specialized behaviors (embraces and same-sex mounts) disproportionately to reconcile. We also found inconsistent evidence for the valuable relationship hypothesis; probabilities of reconciliation were enhanced for male-male dyads with the closest affiliative relationships, but not for those that displayed the most tolerance or mutual agonistic support. We discuss reconciliation and other aspects of conflict management among males in the context of a group with nearly even sex ratios and high male-male mating competition. 相似文献
38.
Nicoleta Dobri Eugenie Emilie Ngueng Oumarou Claudio Alimenti Claudio Ortenzi Pierangelo Luporini Adriana Vallesi 《Gene》2013
Genes encoding the enzyme methionine sulfoxide reductase type B, specific to the reduction of the oxidized methionine-R form, were characterized from the expressed (macronuclear) genome of two ecologically separate marine species of Euplotes, i.e. temperate water E. raikovi and polar water E. nobilii. Both species were found to contain a single msrB gene with a very simple structural organization encoding a protein of 127 (E. raikovi) or 126 (E. nobilii) amino acid residues that belongs to the group of zinc-containing enzymes. Both msrB genes are constitutively expressed, suggesting that the MsrB enzyme plays an essential role in repairing oxidative damages that appear to be primarily caused by physiological cell aging in E. raikovi and by interactions with an O2 saturated environment in E. nobilii. 相似文献
39.
Sébastien Lasvaux Johannes Gantner Bastian Wittstock Manuel Bazzana Nicoleta Schiopu Tom Saunders Cristina Gazulla Jo Ann Mundy Christer Sjöström Pere Fullana-i-Palmer Tim Barrow-Williams Anna Braune Jane Anderson Katrin Lenz Zsoka Takacs Julien Hans Jacques Chevalier 《The International Journal of Life Cycle Assessment》2014,19(11):1783-1793