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841.
Jámbrik K Máthé C Vasas G Beyer D Molnár E Borbély G M-Hamvas M 《Journal of plant physiology》2011,168(7):678-686
Microcystin-LR (MCY-LR), a toxin produced mainly by freshwater cyanobacteria, is a potent inhibitor of type 1 and 2A protein phosphatases. As such, it induces biochemical, cellular and tissue alterations in vascular plants, including cell death. The aim of this study was the analysis of MCY-LR induced changes in the activity of single-strand preferring nuclease (SSP nuclease) isoenzymes that are possibly involved in programmed cell death (PCD) of Phragmites australis (common reed, an aquatic macrophyte) cells. We analyzed both single-stranded DNA (ssDNase) and double-stranded DNA (dsDNase) cleaving activities. Activity gels revealed a number of seven isoenzymes named bands A-G in control reed shoots and roots. Their activity was organ- and age-dependent. We stained nuclei of root tip meristematic cells and found total and marginal chromatin condensations at relatively short-term (2-10 days) cyanotoxin exposure. At 10-20 days of cyanotoxin treatment, the number of cells with condensed chromatin decreased, which coincided with the occurrence of necrotic cell death. In parallel, overall ssDNase activity increased in the short term (five days) and gradually decreased at 10-20 days of MCY-LR treatment. In this context, the most important changes occurred for isoenzyme G of 28-32 kDa in roots and isoenzyme F of 35-38 kDa in shoots. dsDNase activity of isoenzyme E was decreased by MCY-LR in shoots, but increased in roots at 10 days of exposure. We conclude that the early induction of chromatin condensation and increase of SSP nuclease activities is related to PCD that will lead to necrosis with the cease of all cellular activities, including a decrease in nuclease activity. 相似文献
842.
Bekesi A Pukancsik M Haasz P Felfoldi L Leveles I Muha V Hunyadi-Gulyas E Erdei A Medzihradszky KF Vertessy BG 《The FEBS journal》2011,278(2):295-315
Recently, a novel uracil-DNA-degrading factor protein (UDE) was identified in Drosophila melanogaster, with homologues only in pupating insects. Its unique uracil-DNA-degrading activity and a potential domain organization pattern have been described. UDE seems to be the first representative of a new protein family with unique enzyme activity that has a putative role in insect development. In addition, UDE may also serve as potential tool in molecular biological applications. Owing to lack of homology with other proteins with known structure and/or function, de novo data are required for a detailed characterization of UDE structure and function. Here, experimental evidence is provided that recombinant protein is present in two distinct conformers. One of these contains a significant amount of RNA strongly bound to the protein, influencing its conformation. Detailed biophysical characterization of the two distinct conformational states (termed UDE and RNA-UDE) revealed essential differences. UDE cannot be converted into RNA-UDE by addition of the same RNA, implying putatively joint processes of RNA binding and protein folding in this conformational species. By real-time PCR and sequencing after random cloning, the bound RNA pool was shown to consist of UDE mRNA and the two ribosomal RNAs, also suggesting cotranslational RNA-assisted folding. This finding, on the one hand, might open a way to obtain a conformationally homogeneous UDE preparation, promoting successful crystallization; on the other hand, it might imply a further molecular function of the protein. In fact, RNA-dependent complexation of UDE was also demonstrated in a fruit fly pupal extract, suggesting physiological relevance of RNA binding of this DNA-processing enzyme. 相似文献
843.
Jennifer DeWoody Maud Viger Ferenc Lakatos Katalin Tuba Gail Taylor Marinus J. M. Smulders 《PloS one》2013,8(11)
Identifying genetic sequences underlying insect associations on forest trees will improve the understanding of community genetics on a broad scale. We tested for genomic regions associated with insects in hybrid poplar using quantitative trait loci (QTL) analyses conducted on data from a common garden experiment. The F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides) cross were assessed for seven categories of insect leaf damage at two time points, June and August. Positive and negative correlations were detected among damage categories and between sampling times. For example, sap suckers on leaves in June were positively correlated with sap suckers on leaves (P<0.001) but negatively correlated with skeletonizer damage (P<0.01) in August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association occurred among the hybrid offspring, including transgressive segregation of susceptibility to damage. NMDS analyses revealed significant variation and modest broad-sense heritability in insect community structure among genets. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with insect association. We used three genomics tools to test for putative mechanisms underlying the QTL. First, shikimate-phenylpropanoid pathway genes co-located to 9 of the 13 QTL tested, consistent with the role of phenolic glycosides as defensive compounds. Second, two insect association QTL corresponded to genomic hotspots for leaf trait QTL as identified in previous studies, indicating that, in addition to biochemical attributes, leaf morphology may influence insect preference. Third, network analyses identified categories of gene models over-represented in QTL for certain damage types, providing direction for future functional studies. These results provide insight into the genetic components involved in insect community structure in a fast-growing forest tree. 相似文献
844.
Konta L Száraz P Magyar JÉ Révész K Bánhegyi G Mandl J Csala M 《BioFactors (Oxford, England)》2011,37(6):468-476
(-)-Epigallocatechin-3-gallate (EGCG) has been found to trigger the unfolded protein response (UPR) likely due to the inhibition of glucosidase II, a key enzyme of glycoprotein processing and quality control in the endoplasmic reticulum (ER). These findings strongly suggest that EGCG interferes with glycoprotein maturation and sorting in the ER. This hypothesis was tested in SK-Mel28 human melanoma cells by assessing the effect of EGCG and deoxynojirimycin (DNJ) on the synthesis of two endogenous glycoproteins. Both tyrosinase and vascular endothelial growth factor (VEGF) protein levels were remarkably reduced despite unaltered mRNA expression in EGCG- or DNJ-treated cells compared to control. The hindrance of tyrosinase and VEGF protein synthesis could be prevented by proteasome inhibitor, lactacystine. Collectively, our results support that glucosidase II inhibitor EGCG interferes with protein processing and quality control in the ER, which diverts tyrosinase, VEGF, and likely other glycoproteins towards proteasomal degradation. This mechanism provides a novel therapeutic approach in dermatology and might play an important role in the antitumor effect or hepatotoxicity of EGCG. 相似文献
845.
Szomor KN Rigó Z Bán E Nagy L Szalkai T Balogh Z Ferenczi E Takács M 《Acta microbiologica et immunologica Hungarica》2011,58(2):157-167
The presence of WNV in Europe has been well known for decades, although the first human infections and avian outbreaks were diagnosed in Hungary only in 2003. An annual average of 6-8 cases of the neuroinvasive form of WNV infection has been detected in the region since then, but a higher number (17) of WNV associated neuroinvasive disease occurred in 2008. In 2004, a surveillance system was established for monitoring WNV-associated meningo-encephalitis cases in Hungary, but a milder type of illness (with fever, rash and/or influenza like symptoms) is not followed. Fifty-two sera of 45 patients with mild clinical symptoms (fever, exanthema) were tested for anti-WNV antibodies in 2008 in a retrospective study by immunofluorescence test and ELISA. Seven patients had antibodies against WNV, serologic evidence of recent WNV infection was found in 4 out of the 7 patients. Infections could be acquired predominantly in August and in September, which seems to be a risk period for WNV in Hungary. The possibility of a recent WNV infection should be taken into consideration in the occurrence of fever and rush at late summer. Differential diagnosis of exanthematous patients should include WNV serology tests and should be done routinely. 相似文献
846.
In this study, we tested whether the spatial distribution of waterbirds is influenced by shoreline urbanization or other habitat characteristics. We conducted monthly censuses along shoreline sections of a continental lake (Lake Balaton, Hungary) to assess the abundance of 11 common species that use this lake as a feeding and staging area during migration and winter. We estimated the degree of urbanization of the same shoreline sections and also measured other habitat characteristics (water depth, extent of reed cover, biomass of zebra mussels, distances to waste dumps and to other wetlands). We applied linear models and model averaging to identify habitat variables with high relative importance for predicting bird distributions. Bird abundance and urbanization were strongly related only in one species. Other habitat variables exhibited stronger relationships with bird distribution: (1) diving ducks and coots preferred shoreline sections with high zebra mussel biomass, (2) gulls preferred sites close to waste dumps, and (3) the abundances of several species were higher on shoreline sections close to other wetlands. Our findings suggest that the distribution of waterbirds on Lake Balaton is largely independent of shoreline urbanization and influenced by food availability and connectivity between wetlands. 相似文献
847.
László Pecze Zoltán Winter Katalin Jósvay Ferenc Ötvös Csongor Kolozsi Csaba Vizler Dénes Budai Tamás Letoha György Dombi Gerda Szakonyi Zoltán Oláh 《Biological trace element research》2013,151(3):451-461
Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel involved in pain sensation and in a wide range of non-pain-related physiological and pathological conditions. The aim of the present study was to explore the effects of selected heavy metal cations on the function of TRPV1. The cations ranked in the following sequence of pore-blocking activity: Co2+ [half-maximal inhibitory concentration (IC50)?=?13 μM]?>?Cd2+ (IC50?=?38 μM)?>?Ni2+ (IC50?=?62 μM)?>?Cu2+?(IC50?=?200 μM). Zn2+ proved to be a weak (IC50?=?27 μM) and only partial inhibitor of the channel function, whereas Mg2+, Mn2+ and La3+ did not exhibit any substantial effect. Co2+, the most potent channel blocker, was able not only to compete with Ca2+ but also to pass with it through the open channel of TRPV1. In response to heat activation or vanilloid treatment, Co2+ accumulation was verified in TRPV1-transfected cell lines and in the TRPV1+ dorsal root ganglion neurons. The inhibitory effect was also demonstrated in vivo. Co2+ applied together with vanilloid agonists attenuated the nocifensive eye wipe response in mice. Different rat TRPV1 pore point mutants (Y627W, N628W, D646N and E651W) were created that can validate the binding site of previously used channel blockers in agonist-evoked 45Ca2+ influx assays in cells expressing TRPV1. The IC50 of Co2+ on these point mutants were determined to be reasonably comparable to those on the wild type, which suggests that divalent cations passing through the TRPV1 channel use the same negatively charged amino acids as Ca2+. 相似文献
848.
849.
Laboratory and field experiments were carried out for bioremediation of soils contaminated by fuel oil and motor oil. Bioventing was combined with the application of selected bacteria and dissolved nutrients. In the field experiments, soil gas was evacuated by air pumps from the permeable boreholes. The process was followed by both soil and gas analysis. Biodegradation of oil contamination and the microbial activity was measured by the oil and cell concentration in the soil. In 2 months, the oil content decreased considerably, and the cell number increased by one order of magnitude or more. The evacuated gas was tested for CO2, O2 and volatilized hydrocarbon content. The CO2 level proves the presence of biodegradation: a permanent high value about ten times higher than normal, could be measured for 2 months, followed by a slow decrease in the third month. Volatilized hydrocarbon content was the highest in the first 2 d. After a continuous decrease, it dropped under the threshold of measurability for the third month. Selective biodegradation of hydrocarbon mixtures (oily wastes) was investigated as well: gas Chromatographic oil analysis showed the changes in the oil composition. The appropriate microflora was working in an ideal commensalism, and as a result, all of the hydrocarbon components were degraded nearly to the same extent. 相似文献
850.
Krisztian Kasos Szabolcs Zimonyi Eniko Kasos Avraham Lifshitz Katalin Varga Anna Szekely 《Applied psychophysiology and biofeedback》2018,43(3):203-210
Traditionally, electrodermal research measurements were taken from the non-dominant hand. This was considered a valid measurement of arousal for the whole body. Some, however argue for a complex and asynchronous electrodermal system in terms of lateral and dermatome differences in emotional responding. The present study measured skin conductance responses to emotionally laden musical stimuli from the left and right index and middle fingers, as well as the left and right plantar surface of right handed participants (N?=?39). The 7-s musical segments conveyed four emotional categories: fear, sadness, happiness and peacefulness. Our results suggest, that the electrodermal system responds to emotional musical stimuli in a lateralized manner on the palmar surfaces. Fear, sadness and peacefulness prompted right hand dominance while happiness elicited left hand dominant response. Lateralization of the palmar and plantar surfaces differed significantly. Moreover, an association between lateralization of the electrodermal system in response to fear and state anxiety was found. Results of the present study suggest that the electrodermal system displays lateral preferences, reacting with varying degree of intensity to different emotions. Apart from lateral differences, music induced emotions show dermatome differences as well. These findings fit well with Multiple Arousal Theory, and prompt for revaluating the notion of uniform electrodermal arousal. 相似文献