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991.
Zoltán Bátori László Erdős András Kelemen Balázs Deák Orsolya Valkó Róbert Gallé Tatyana M. Bragina Péter János Kiss György Kröel-Dulay Csaba Tölgyesi 《Biodiversity and Conservation》2018,27(4):1011-1030
The Palearctic forest-steppe biome is a narrow vegetation zone between the temperate forest and steppe biomes, which provides important habitats for many endangered species and represents an important hotspot of biodiversity. Although the number of studies on forest–grassland mosaics is increasing, information currently available about the general compositional and structural patterns of Eurasian forest-steppes is scarce. Our study aimed to compare the habitat structure, species composition and diversity patterns of two distant sandy forest-steppes of Eurasia. We compared 72 relevés made in the main habitat components (forest, forest edge and grassland) of sandy forest-steppes in three Hungarian and three Kazakh sites. The size of the plots was 25 m2. Species number, Shannon diversity and species evenness values were calculated for each plot. Fidelity calculations and linear mixed effects models were used for the analyses. We found that the vegetation and diversity patterns of the two forest-steppes are similar and their components play important roles in maintaining landscape-scale diversity. Despite the higher species richness in Hungary, Shannon diversity was higher in Kazakhstan. The deciduous forest edges of both areas had significantly higher species richness than the neighbouring habitats (forests and grasslands); therefore they can be considered local biodiversity hotspots. Due to the special characteristics of this vegetation complex, we emphasize the high conservation value of all landscape components as a coherent system throughout the entire range of the Eurasian forest-steppe biome. 相似文献
992.
Delfourne E Kiss R Le Corre L Merza J Bastide J Frydman A Darro F 《Bioorganic & medicinal chemistry》2003,11(20):4351-4356
The isomer (9H-quino[4,3,2-de][1,7]phenanthroline-9-one) (2) of the marine alkaloid ascididemin (9H-quino[4,3,2-de][1,10]phenanthroline-9-one) (1) has been synthesized in six steps from 1,4-dimethoxyacridine (10) with an overall yield of 12%. Different related compounds were prepared and tested in vitro at six different concentrations on 12 different human cancer cell lines of various histopathological types (glioblastomas and breast, colon, lung, prostate and bladder cancers). Almost all the compounds present cytotoxic activity of micromolar order. 相似文献
993.
Earlier we showed that in serum-starved fibroblasts placental alkaline phosphatase (PALP) can exert growth factor-like effects. Here we report that in mouse embryo (NIH 3T3) and human fetus (HTB-157) fibroblasts, PALP (200 nM) alone provided full protection against serum starvation-induced cell death for 5 days. After 12 days, substantial effects of PALP on cell survival required the copresence of insulin (500 nM) and ATP or adenosine (100 microM). In serum-starved NIH 3T3 cells, PALP induced activating phosphorylation of p42/p44 mitogen-activated protein (MAP) kinases; insulin, but not ATP, had small additional effects. PALP also stimulated the expression of various cyclins; ATP both prolonged and enhanced PALP-induced expression of cyclins A and E. Finally, ATP/adenosine enhanced activation of Akt kinase by insulin. The results suggest that PALP may be a regulator of growth and remodeling of fetal tissues during the second and third trimester of pregnancy when it is expressed. 相似文献
994.
Gene mining in halophytes: functional identification of stress tolerance genes in Lepidium crassifolium 下载免费PDF全文
Dóra Faragó Edina Kiss Sara Van Houdt Nancy Van de Steene Matthew A. Hannah László Szabados 《Plant, cell & environment》2016,39(9):2074-2084
Extremophile plants are valuable sources of genes conferring tolerance traits, which can be explored to improve stress tolerance of crops. Lepidium crassifolium is a halophytic relative of the model plant Arabidopsis thaliana, and displays tolerance to salt, osmotic and oxidative stresses. We have employed the modified Conditional cDNA Overexpression System to transfer a cDNA library from L. crassifolium to the glycophyte A. thaliana. By screening for salt, osmotic and oxidative stress tolerance through in vitro growth assays and non‐destructive chlorophyll fluorescence imaging, 20 Arabidopsis lines were identified with superior performance under restrictive conditions. Several cDNA inserts were cloned and confirmed to be responsible for the enhanced tolerance by analysing independent transgenic lines. Examples include full‐length cDNAs encoding proteins with high homologies to GDSL‐lipase/esterase or acyl CoA‐binding protein or proteins without known function, which could confer tolerance to one or several stress conditions. Our results confirm that random gene transfer from stress tolerant to sensitive plant species is a valuable tool to discover novel genes with potential for biotechnological applications. 相似文献
995.
Gerg? Gógl Anita Alexa Bence Kiss Gergely Katona Mihály Kovács Andrea Bodor Attila Reményi László Nyitray 《The Journal of biological chemistry》2016,291(1):11-27
Mitogen-activated protein kinases (MAPK) promote MAPK-activated protein kinase activation. In the MAPK pathway responsible for cell growth, ERK2 initiates the first phosphorylation event on RSK1, which is inhibited by Ca2+-binding S100 proteins in malignant melanomas. Here, we present a detailed in vitro biochemical and structural characterization of the S100B-RSK1 interaction. The Ca2+-dependent binding of S100B to the calcium/calmodulin-dependent protein kinase (CaMK)-type domain of RSK1 is reminiscent of the better known binding of calmodulin to CaMKII. Although S100B-RSK1 and the calmodulin-CAMKII system are clearly distinct functionally, they demonstrate how unrelated intracellular Ca2+-binding proteins could influence the activity of the CaMK domain-containing protein kinases. Our crystallographic, small angle x-ray scattering, and NMR analysis revealed that S100B forms a “fuzzy” complex with RSK1 peptide ligands. Based on fast-kinetics experiments, we conclude that the binding involves both conformation selection and induced fit steps. Knowledge of the structural basis of this interaction could facilitate therapeutic targeting of melanomas. 相似文献
996.
997.
Lassoie MA Broeders F Collart P Defrère L de Laveleye-Defais F Demaude T Gassama A Guillaumet G Hayez JC Kiss L Knerr L Nicolas JM Norsikian S Quéré L Routier S Verbois V Provins L 《Bioorganic & medicinal chemistry letters》2007,17(1):142-146
A new series of 2,6-quinolinyl derivatives was prepared leading to potent low nanomolar VLA-4/VCAM-1 antagonists. 相似文献
998.
Maria Palmieri Melissa A. Schwind Martin Henry H. Stevens Richard E. Edelmann John Z. Kiss 《Physiologia plantarum》2007,130(4):613-626
The actin cytoskeleton is a crucial component in plant gravitropism, and studies confirm that alterations to actin filaments (F-actin) can have dramatic effects on gravitropic curvature in roots and shoots. Many models for gravisensing in higher plants suggest that the key to gravity perception and signal transduction lies in intimate interactions between F-actin and amyloplasts. In this study, we investigated gravitropism in hypocotyls by analyzing the effect of myosin inhibition on gravitropic curvature in order to clarify the role of the actomyosin system in shoot gravitropism. To study amyloplast movement in endodermal cells (i.e., gravity-perceiving statocytes) of living seedlings, we repositioned a confocal laser scanning microscope (CLSM) so that its rotatable stage was oriented vertically. Seedlings containing green fluorescent protein-labeled endodermal amyloplasts were incubated with the ATPase inhibitor 2,3-butanedione monoxime (BDM) and then mounted on the stage so that the hypocotyls were vertical. Using CLSM, we imaged the endodermal amyloplasts, while the hypocotyls were oriented vertically and also after they were reoriented by 90°. Our results show that BDM reduces gravitropic curvature in a concentration-dependent manner. In addition, BDM increases amyloplast movement in hypocotyls of vertical seedlings, but reduces amyloplast movement in hypocotyls of reoriented seedlings, suggesting that myosin may participate in the intracellular transport of amyloplasts in statocytes. These results can be explained in the context of amyloplasts as both noise indicators and gravity susceptors, with BDM producing less coherent amyloplast movement that results in an increased signal-to-noise ratio, which may account for at least part of the observed reduction in gravitopic curvature. 相似文献
999.
3-hydroxy-3-methylglutaryl coenzyme a reductase 1 interacts with NORK and is crucial for nodulation in Medicago truncatula 下载免费PDF全文
Kevei Z Lougnon G Mergaert P Horváth GV Kereszt A Jayaraman D Zaman N Marcel F Regulski K Kiss GB Kondorosi A Endre G Kondorosi E Ané JM 《The Plant cell》2007,19(12):3974-3989
NORK in legumes encodes a receptor-like kinase that is required for Nod factor signaling and root nodule development. Using Medicago truncatula NORK as bait in a yeast two-hybrid assay, we identified 3-hydroxy-3-methylglutaryl CoA reductase 1 (Mt HMGR1) as a NORK interacting partner. HMGR1 belongs to a multigene family in M. truncatula, and different HMGR isoforms are key enzymes in the mevalonate biosynthetic pathway leading to the production of a diverse array of isoprenoid compounds. Testing other HMGR members revealed a specific interaction between NORK and HMGR1. Mutagenesis and deletion analysis showed that this interaction requires the cytosolic active kinase domain of NORK and the cytosolic catalytic domain of HMGR1. NORK homologs from Lotus japonicus and Sesbania rostrata also interacted with Mt HMGR1, but homologous nonsymbiotic kinases of M. truncatula did not. Pharmacological inhibition of HMGR activities decreased nodule number and delayed nodulation, supporting the importance of the mevalonate pathway in symbiotic development. Decreasing HMGR1 expression in M. truncatula transgenic roots by RNA interference led to a dramatic decrease in nodulation, confirming that HMGR1 is essential for nodule development. Recruitment of HMGR1 by NORK could be required for production of specific isoprenoid compounds, such as cytokinins, phytosteroids, or isoprenoid moieties involved in modification of signaling proteins. 相似文献
1000.
Hofner P Gyulai Z Kiss ZF Tiszai A Tiszlavicz L Tóth G Szõke D Molnár B Lonovics J Tulassay Z Mándi Y 《Helicobacter》2007,12(2):124-131
BACKGROUND: Intracellular pathogen receptor NOD1 is involved in the epithelial cell sensing Helicobacter pylori, which results in a considerable interleukin (IL)-8 production. The aim of this study was to evaluate the relationship between NOD1 and IL-8 genetic polymorphisms and the development of H. pylori-induced gastritis and duodenal ulcer (DU), as compared with TLR4 polymorphisms. MATERIALS AND METHODS: Eighty-five patients with DU and 135 patients with gastritis were enrolled in the study. Seventy-five serologically H. pylori-positive subjects without gastric or duodenal symptoms served as controls. The G796A (E266K) NOD1 polymorphism was determined by restriction fragment length polymorphism, and the -251 IL-8 polymorphism by amplification refractory mutation system method. The TLR4 (ASP/299/Gly and Thr/399/Ile) gene polymorphisms were examined by melting point analysis. RESULTS: AA homozygote mutant variants of NOD1 were detected in 20% of the H. pylori-positive patients with DU versus 7% of H. pylori-positive patients with gastritis and versus 6% of the H. pylori-positive healthy controls. The IL-8 heterozygote mutant variant was detected with a significantly higher frequency among the DU patients and those with gastritis than among the H. pylori-positive controls. However, no significant correlation concerning the frequency of the TLR4 gene polymorphism could be revealed between any group of patients and the controls. CONCLUSION: E266K CARD4/NOD1, but not the TLR4 gene polymorphism increases the risk of peptic ulceration in H. pylori-positive patients. The -251 IL-8 polymorphism was significantly associated with either gastritis or DU in H. pylori-infected subjects. Host factors including intracellular pathogen receptors and IL-8 production play an important role in H. pylori-induced gastric mucosal damage. 相似文献