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151.
152.
King BC Nowakowska J Karsten CM Köhl J Renström E Blom AM 《Journal of immunology (Baltimore, Md. : 1950)》2012,188(8):4103-4112
Thioredoxin (Trx)-1 is a small, ubiquitously expressed redox-active protein with known important cytosolic functions. However, Trx1 is also upregulated in response to various stress stimuli, is found both at the cell surface and secreted into plasma, and has known anti-inflammatory and antiapoptotic properties. Previous animal studies have demonstrated that exogenous Trx1 delivery can have therapeutic effects in a number of disease models and have implicated an interaction of Trx1 with the complement system. We found that Trx1 is expressed in a redox-active form at the surface of HUVEC and acts as an inhibitor of complement deposition in a manner dependent on its Cys-Gly-Pro-Cys active site. Inhibition occurred at the point of the C5 convertase of complement, regulating production of C5a and the membrane attack complex. A truncated form of Trx1 also exists in vivo, Trx80, which has separate nonoverlapping functions compared with the full-length Trx1. We found that Trx80 activates the classical and alternative pathways of complement activation, leading to C5a production, but the inflammatory potential of this was also limited by the binding of inhibitors C4b-binding protein and factor H. This study adds a further role to the known anti-inflammatory properties of Trx1 and highlights the difference in function between the full-length and truncated forms. 相似文献
153.
Korycka J Łach A Heger E Bogusławska DM Wolny M Toporkiewicz M Augoff K Korzeniewski J Sikorski AF 《European journal of cell biology》2012,91(2):107-117
Palmitoylation is one of the most common posttranslational lipid modifications of proteins and we now know quite a lot about it. However, the state of knowledge about the enzymes that catalyze this process is clearly insufficient. This review is focused on 23 human DHHC genes and their products - protein palmitoyltransferases. Here we describe mainly the structure and function of these proteins, but also, to a lesser degree, what the substrates of the enzymes are and whether they are related to various diseases. The main aim of this review was to catalogue existing information concerning the human DHHC family of genes/proteins, making them and their functions easier to understand. 相似文献
154.
A new regioselective method of di-gem-thio-substituted PNP-crown derivatives synthesis is presented. The geminalmercaptoethanolanetricyclophosphaza-PNP-lariat ether structure has been determined by X-ray crystallography and characterised by ab initio calculations. The 16-membered PNP-crown ether ring exists in unique conformation: ac−ap ac−sc+sc+ap sc+ap ap sc−ap sc−sc−ac+ap ac+. All the ether oxygen atoms are directed into the interior of the ring. All endocyclic P-N bond lengths are equal within experimental error with the mean value 1.578(2) Å. The P-S bond properties have been characterised in terms of natural bond orbital (NBO) analysis, and its interactions with other NBO have been described. The spirocyclisation mechanism at cyclophosphazene phosphorus atom has been proposed. 相似文献
155.
One severe aplastic anaemia case who presented autoimmune thyroid disease after allogeneic bone marrow transplantation (alloBMT) is described. A 19 year old Polish girl developed Graves' hyperthyroidisms 19 months after allogeneic BMT for severe aplastic anaemia (SAA) donated from her brother. Her serum was positive for thyroid stimulating antibody (TSAb) and anti-thyroid peroxidase autoantibodies (aTPO) while her brother remained euthyroid, seronegative for TSAb, and showed no clinical signs of thyroid pathology. The genetic studies of lymphocytes FISH (fluorescence in situ hybridization) and analysis of STR (short tandem repeated) fragments suggested, that lymphocytes responsible for hyperthyroidisms were of donor origin. 相似文献
156.
The polarization of a neuron generally results in the formation of one axon and multiple dendrites, allowing for the establishment of neuronal circuitry. The molecular mechanisms involved in priming one neurite to become the axon, particularly those regulating the microtubule network, remain elusive. Here we report the identification of DOCK7, a member of the DOCK180-related protein superfamily, as a Rac GTPase activator that is asymmetrically distributed in unpolarized hippocampal neurons and selectively expressed in the axon. Knockdown of DOCK7 expression prevents axon formation, whereas overexpression induces formation of multiple axons. We further demonstrate that DOCK7 and Rac activation lead to phosphorylation and inactivation of the microtubule destabilizing protein stathmin/Op18 in the nascent axon and that this event is important for axon development. Our findings unveil a pathway linking the Rac activator DOCK7 to a microtubule regulatory protein and highlight the contribution of microtubule network regulation to axon development. 相似文献
157.
Wolinska J Bittner K Ebert D Spaak P 《Proceedings. Biological sciences / The Royal Society》2006,273(1596):1977-1983
Parasite driven time-lagged negative frequency-dependent selection of hosts has been studied in natural populations by following changes in host genotype frequencies over time. However, such dynamics have not been considered at higher taxonomic levels, for example, between parental species and their hybrids. In a field study on a Daphnia hybrid system, we observed that one Daphnia taxon first was relatively under-infected, but became over-infected after a strong increase in frequency. This finding is consistent with the idea of parasite evolution towards the most frequent host taxon. In two experiments, we investigated whether the assumptions made by a model of negative frequency-dependent selection apply to our host taxa system. First, we showed that the parasite can change the outcome of taxa competition and secondly, we confirmed that the over-infection of one host taxon observed in the field has a genetic basis. Our results indicate that the incorporation of host-parasite interactions at the species level may allow us to gain a more complete picture of forces driving dynamic taxa coexistence in Daphnia hybrid systems. More generally, we suggest that if hybrids coexist in sympatry with parental taxa, the infection patterns as observed under natural conditions may be rather temporal and unstable. 相似文献
158.
Justyna Teresa Polit 《Plant cell reports》2009,28(2):165-173
Before Vicia faba root meristem cells stopped by carbohydrate starvation in principal control points (PCP1 and PCP2) start sucrose induced
replication and division they go through a phase of metabolic regeneration. This interval is characterised st great sensitivity
to the inhibitors of cyclin-dependent protein kinases and protein phosphatases (PPs). In the present research, changes of
phosphoprotein levels in the nucleolus, nucleus and cytoplasm were analysed using okadaic acid and 6-dimethylaminopurine (6-DMAP)
during the first period of cell regeneration in sucrose (0–3 h). It was established that when the cells start to leave checkpoints,
the balance between protein phosphorylation and dephosphorylation shifts towards the intensified activity of PPs. Furthermore,
it was also established that the structures appearing during cell regeneration, which were located around cell nuclei and
which contained large amounts of phosphorylated proteins, were plastids. The reactions of protein phosphorylation which took
place in the plastids were directly correlated with starch synthesis and were stopped by inactivation of protein phosphatases
(PP1 and/or PP2A). 相似文献
159.
Witold K. Subczynski Justyna Widomska Jimmy B. Feix 《Free radical biology & medicine》2009,46(6):707-718
The influence of a variety of microenvironmental factors on the inherent reactivity of membrane-located reagents is poorly understood. A goal of this review is to provide detailed profiles of membrane properties, including hydrophobicity, oxygen and nitric oxide solubility and diffusion rates, bilayer penetration of metal ions and metal-ion complexes, and membrane order and fluidity, that can be obtained with EPR spin-labeling methods. These properties can drastically vary with membrane composition, membrane depth, and membrane domain formation, influencing the fate of chemical reactions that occur in a lipid bilayer environment. 相似文献
160.
Carlos Martinez-Fleites Justyna E. Korczynska Gideon J. Davies Matthew J. Cope Johan P. Turkenburg Edward J. Taylor 《Carbohydrate research》2009,344(13):1753-1757
Lysozymes are found in many of the sequence-based families of glycoside hydrolases (www.cazy.org) where they show considerable structural and mechanistic diversity. Lysozymes from glycoside hydrolase family GH25 adopt a (α/β)5(β)3-barrel-like fold with a proposal in the literature that these enzymes act with inversion of anomeric configuration; the lack of a suitable substrate, however, means that no group has successfully demonstrated the configuration of the product. Here we report the 3-D structure of the GH25 enzyme from Bacillus anthracis at 1.4 Å resolution. We show that the active center is extremely similar to those from glycoside hydrolase families GH18, GH20, GH56, GH84, and GH85 implying that, in the absence of evidence to the contrary, GH25 enzymes also act with net retention of anomeric configuration using the neighboring-group catalytic mechanism that is common to this ‘super-family’ of enzymes. 相似文献