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101.
Natalia E. Kichigina Jan V. Puhalsky Aleksander I. Shaposhnikov Tatiana S. Azarova Natalia M. Makarova Svyatoslav I. Loskutov Vera I. Safronova Igor A. Tikhonovich Margarita A. Vishnyakova Elena V. Semenova Irina A. Kosareva Andrey A. Belimov 《Physiology and Molecular Biology of Plants》2017,23(4):851-863
Our study aimed to evaluate intraspecific variability of pea (Pisum sativum L.) in Al tolerance and to reveal mechanisms underlying genotypic differences in this trait. At the first stage, 106 pea genotypes were screened for Al tolerance using root re-elongation assay based on staining with eriochrome cyanine R. The root re-elongation zone varied from 0.5 mm to 14 mm and relationships between Al tolerance and provenance or phenotypic traits of genotypes were found. Tolerance index (TI), calculated as a biomass ratio of Al-treated and non-treated contrasting genotypes grown in hydroponics for 10 days, varied from 30% to 92% for roots and from 38% to 90% for shoots. TI did not correlate with root or shoot Al content, but correlated positively with increasing pH and negatively with residual Al concentration in nutrient solution in the end of experiments. Root exudation of organic acid anions (mostly acetate, citrate, lactate, pyroglutamate, pyruvate and succinate) significantly increased in several Al-treated genotypes, but did not correlate with TI. Al-treatment decreased Ca, Co, Cu, K, Mg, Mn, Mo, Ni, S and Zn contents in roots and/or shoots, whereas contents of several elements (P, B, Fe and Mo in roots and B and Fe in shoots) increased, suggesting that Al toxicity induced substantial disturbances in uptake and translocation of nutrients. Nutritional disturbances were more pronounced in Al sensitive genotypes. In conclusion, pea has a high intraspecific variability in Al tolerance and this trait is associated with provenance and phenotypic properties of plants. Transformation of Al to unavailable (insoluble) forms in the root zone and the ability to maintain nutrient uptake are considered to be important mechanisms of Al tolerance in this plant species. 相似文献
102.
103.
Pietrovski EF Otuki MF Regoli D Bader M Pesquero JB Cabrini DA Zampronio AR 《Regulatory peptides》2009,152(1-3):67-72
Peptide and non-peptide kinin receptor antagonists were evaluated in cutaneous inflammation models in mice. Topical and i.p. application of kinin B(1) and B(2) receptor antagonists caused a significant inhibition of the capsaicin-induced cutaneous neurogenic inflammatory response. The calculated mean ID(50) for Hoe140 and SSR240612 were 23.83 (9.14-62.14) nmol/kg and 0.23 (0.15-0.36) mg/ear, respectively. The I(max) observed for Hoe140, SSR240612, R-715, FR173657, and FR plus SSR were 61+/-5%, 56+/-3%, 65+/-10%, 48+/-8%, and 52+/-4%, respectively. Supporting these results, double B(1) and B(2) kinin receptors knockout mice showed a significant inhibition of capsaicin-induced ear oedema (42+/-7%). However, mice with a single deletion of either B(1) or B(2) receptors exhibited no change in their capsaicin responses. In contrast, all of the examined kinin receptor antagonists were unable to inhibit the oedema induced by TPA and the results from knockout mice confirmed the lack of kinin receptor signaling in this model. These findings show that kinin receptors are present in the skin and that both kinin receptors seem to be important in the neurogenic inflammatory response. Moreover, non-peptide antagonists were very effective in reducing skin inflammation when topically applied, thereby suggesting that they could be useful tools in the treatment of some skin inflammatory diseases. 相似文献
104.
105.
Exogenous treatment with salicylic acid attenuates cadmium toxicity in pea seedlings 总被引:1,自引:0,他引:1
Losanka P. Popova Liliana T. Maslenkova Rusina Y. Yordanova Albena P. Ivanova Aleksander P. Krantev Gabriella Szalai Tibor Janda 《Plant Physiology and Biochemistry》2009,47(3):224-231
The present study investigated the possible mediatory role of salicylic acid (SA) in protecting plants from cadmium (Cd) toxicity. The exposure of pea plants to increasing Cd concentrations (0.5, 1.0, 2.0 and 5.0 μM) during early stages of their establishment, caused a gradual decrease in shoot and root fresh weight accumulation, the rate of CO2 fixation and the activity of ribulose-1,5-bisphosphate carboxylase (RuBPC, E.C. 4.1.1.39), the effect being most expressed at higher Cd concentrations. In vivo the excess of Cd-induced alterations in the redox cycling of oxygen-evolving centers and the assimilatory capacity of the pea leaves as revealed by changes in thermoluminescence emission after flash illumination. The levels of some important parameters associated with oxidative stress, namely lipid peroxidation, electrolyte leakage and proline production were increased. Seed pretreatment with SA alleviated the negative effect of Cd on growth, photosynthesis, carboxylation reactions, thermoluminescence characteristics and chlorophyll content, and led to decrease in oxidative injuries caused by Cd. The data suggest that the beneficial effect of SA during an earlier growth period could be related to avoidance of cumulative damage upon exposure to cadmium thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity. In addition, the observed high endogenous levels of SA after treatment with Cd suggests that SA may act directly as an antioxidant to scavenge the reactive oxygen species and/or indirectly modulate redox balance through activation of antioxidant responses.Taken together these evidences could explain at some extend the protective role of SA on photochemical activity of chloroplast membranes and photosynthetic carboxylation reactions in Cd-stressed pea plants. 相似文献
106.
Jolanta Idkowiak-Baldys Aleksander Baldys John R. Raymond Yusuf A. Hannun 《The Journal of biological chemistry》2009,284(33):22322-22331
Considerable insight has been garnered on initial mechanisms of endocytosis of plasma membrane proteins and their subsequent trafficking through the endosomal compartment. It is also well established that ligand stimulation of many plasma membrane receptors leads to their internalization. However, stimulus-induced regulation of endosomal trafficking has not received much attention. In previous studies, we showed that sustained stimulation of protein kinase C (PKC) with phorbol esters led to sequestration of recycling endosomes in a juxtanuclear region. In this study, we investigated whether G-protein-coupled receptors that activate PKC exerted effects on endosomal trafficking. Stimulation of cells with serotonin (5-hydroxytryptamine (5-HT)) led to sequestration of the 5-HT receptor (5-HT2AR) into a Rab11-positive juxtanuclear compartment. This sequestration coincided with translocation of PKC as shown by confocal microscopy. Mechanistically the observed sequestration of 5-HT2AR was shown to require continuous PKC activity because it was inhibited by pretreatment with classical PKC inhibitor Gö6976 and could be reversed by posttreatment with this inhibitor. In addition, classical PKC autophosphorylation was necessary for receptor sequestration. Moreover inhibition of phospholipase D (PLD) activity and inhibition of PLD1 and PLD2 using dominant negative constructs also prevented this process. Functionally this sequestration did not affect receptor desensitization or resensitization as measured by intracellular calcium increase. However, the PKC- and PLD-dependent sequestration of receptors resulted in co-sequestration of other plasma membrane proteins and receptors as shown for epidermal growth factor receptor and protease activated receptor-1. This led to heterologous desensitization of those receptors and diverted their cellular fate by protecting them from agonist-induced degradation. Taken together, these results demonstrate a novel role for sustained receptor stimulation in regulation of intracellular trafficking, and this process requires sustained stimulation of PKC and PLD.The protein kinase C (PKC)2 family of enzymes comprises 11 isoforms of serine/threonine kinases (1, 2) implicated in regulation of cell growth, differentiation, apoptosis, secretion, neurotransmission, and signal transduction (3–5). During the course of studying PKC, we showed that sustained stimulation of PKC with phorbol esters leads to translocation of classical PKC (cPKC) to a pericentrosomal region (6, 7). This sequestration was shown to be PLD-dependent (8, 9) and negatively regulated by ceramide formed from the salvage pathway (10). Ceramide inhibits autophosphorylation of cPKC, which was also found to be required for this novel translocation (11). Importantly sustained activation of cPKC also resulted in significant effects on recycling components and their sequestration to the same region, dubbed the pericentrion (defined as the cPKC-dependent subset of recycling endosomes). On the other hand, components and markers of the endolysosomal compartment were not sequestered to the pericentrion upon PKC stimulation (7). Functionally it was also shown that pericentrion formation and sequestration of PKC requires clathrin-dependent endocytosis. Most importantly, formation of the pericentrion is dynamic and reversible and requires continuous activation of PKC.G-protein-coupled receptors (GPCRs) are the largest family of integral membrane receptors. They contain seven transmembrane domains (12), are coupled to heterotrimeric G-proteins, and are activated by a vast number of ligands. They regulate many cellular processes and serve as targets for at least half of the therapeutics currently present on the market. Upon agonist binding, conformational changes in the receptor lead to coupling with G-proteins (composed of α, β, and γ subunits). This leads to dissociation of α and β/γ subunits that mediate downstream signaling (13). Interestingly PKC serves as one of the downstream targets of GPCRs. Thus, it became critical to determine whether persistent stimulation of receptors that couple to cPKC exerts effects on recycling endosomes. We focused on the serotonin (5-HT) 5-HT2A receptor (5-HT2AR) and the angiotensin II receptor (AT1AR) as two GPCRs that couple to Gq, which in turn activates phospholipase Cβ and then PKC (14, 15).In this study, we show that sustained stimulation of those receptors led to their sequestration in a PKC- and PLD-dependent manner. Most importantly, this led to global sequestration of endosomes with profound effects on other membrane receptors. Epidermal growth factor receptor (EGFR) and protease activated receptor-1 (PAR-1) are known to be targeted into a degradative pathway upon their agonist treatment (16–18). Interestingly 5-HT induced co-sequestration of those receptors with 5-HT2AR and protected them from degradation upon their own agonist treatment. The implications of these results on regulation of trafficking by GPCRs are discussed. 相似文献
107.
108.
Joana RF Abreu Daphne de Launay Marjolein E Sanders Aleksander M Grabiec G Marleen van de Sande Paul P Tak Kris A Reedquist 《Arthritis research & therapy》2009,11(4):R121-13
Introduction
Fibroblast-like synoviocytes (FLS) from rheumatoid arthritis (RA) patients share many similarities with transformed cancer cells, including spontaneous production of matrix metalloproteinases (MMPs). Altered or chronic activation of proto-oncogenic Ras family GTPases is thought to contribute to inflammation and joint destruction in RA, and abrogation of Ras family signaling is therapeutic in animal models of RA. Recently, expression and post-translational modification of Ras guanine nucleotide releasing factor 1 (RasGRF1) was found to contribute to spontaneous MMP production in melanoma cancer cells. Here, we examine the potential relationship between RasGRF1 expression and MMP production in RA, reactive arthritis, and inflammatory osteoarthritis synovial tissue and FLS. 相似文献109.
Anna Chorzalska Agnieszka Łach Tomasz Borowik Marcin Wolny Anita Hryniewicz-Jankowska Adam Kolondra Marek Langner Aleksander F. Sikorski 《Cellular & molecular biology letters》2010,15(3):406-423
It was previously shown that the beta-spectrin ankyrin-binding domain binds lipid domains rich in PE in an ankyrin-dependent
manner, and that its N-terminal sequence is crucial in interactions with phospholipids. In this study, the effect of the full-length
ankyrin-binding domain of β-spectrin on natural erythrocyte and HeLa cell membranes was tested. It was found that, when encapsulated
in resealed erythrocyte ghosts, the protein representing the full-length ankyrin-binding domain strongly affected the shape
and barrier properties of the erythrocyte membrane, and induced partial spectrin release from the membrane, while truncated
mutants had no effect. As found previously (Bok et al. Cell Biol. Int. 31 (2007) 1482–94), overexpression of the full-length GFP-tagged ankyrin-binding domain aggregated and induced aggregation of
endogenous spectrin, but this was not the case with overexpression of proteins truncated at their N-terminus. Here, we show
that the aggregation of spectrin was accompanied by the aggregation of integral membrane proteins that are known to be connected
to spectrin via ankyrin, i.e. Na+K+ATP-ase, IP3 receptor protein and L1 CAM. By contrast, the morphology of the actin cytoskeleton remained unchanged and aggregation
of cadherin E or N did not occur upon the overexpression of either full-length or truncated ankyrin-binding domain proteins.
The obtained results indicate a substantial role of the lipid-binding part of the β-spectrin ankyrin-binding domain in the
determination of the membrane and spectrin-based skeleton functional properties. 相似文献
110.
Ekaterini Blaveri Fiona Kelly Alessandra Mallei Kriss Harris Adam Taylor Juliet Reid Maria Razzoli Lucia Carboni Chiara Piubelli Laura Musazzi Girogio Racagni Aleksander Mathé Maurizio Popoli Enrico Domenici Stewart Bates 《PloS one》2010,5(9)