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71.
An N-terminal diacidic motif is required for the trafficking of maize aquaporins ZmPIP2;4 and ZmPIP2;5 to the plasma membrane 总被引:1,自引:0,他引:1
Zelazny E Miecielica U Borst JW Hemminga MA Chaumont F 《The Plant journal : for cell and molecular biology》2009,57(2):346-355
Maize plasma membrane aquaporins (ZmPIPs, where PIP is the plasma membrane intrinsic protein) fall into two groups, ZmPIP1s and ZmPIP2s, which, when expressed alone in mesophyll protoplasts, are found in different subcellular locations. Whereas ZmPIP1s are retained in the endoplasmic reticulum (ER), ZmPIP2s are found in the plasma membrane (PM). We previously showed that, when co-expressed with ZmPIP2s, ZmPIP1s are relocalized to the PM, and that this relocalization results from the formation of hetero-oligomers between ZmPIP1s and ZmPIP2s. To determine the domains responsible for the ER retention and PM localization, respectively, of ZmPIP1s and ZmPIP2s, truncated and mutated ZmPIPs were generated, together with chimeric proteins created by swapping the N- or C-terminal regions of ZmPIP2s and ZmPIP1s. These mutated proteins were fused to the mYFP and/or mCFP, and the fusion proteins were expressed in maize mesophyll protoplasts, and were then localized by microscopy. This allowed us to identify a diacidic motif, DIE (Asp-Ile-Glu), at position 4–6 of the N-terminus of ZmPIP2;5, that is essential for ER export. This motif was conserved and functional in ZmPIP2;4, but was absent in ZmPIP2;1. In addition, we showed that the N-terminus of ZmPIP2;5 was not sufficient to cause the export of ZmPIP1;2 from the ER. A study of ZmPIP1;2 mutants suggested that the N- and C-termini of this protein are probably not involved in ER retention. Together, these results show that the trafficking of maize PM aquaporins is differentially regulated depending on the isoform, and involves a specific signal and mechanism. 相似文献
72.
J. Julio Camarero Juan Carlos Linares Ana I. García-Cervigón Enric Batllori Isabel Martínez Emilia Gutiérrez 《Ecosystems》2017,20(4):683-700
Alpine treeline ecotones are considered early-warning monitors of the effects of climate change on terrestrial ecosystems, but it is still unclear how accurately treeline dynamics may track the expected temperature rises. Site-specific abiotic constraints, such as topography and demographic trends may make treelines less responsive to environmental fluctuations. A better understanding on how local processes modulate treelines’ response to warming is thus required. We developed a model of treeline dynamics based on individual data of growth, mortality and reproduction. Specifically, we modeled growth patterns, mortality rates and reproductive size thresholds as a function of temperature and stand structure to evaluate the influence of climate- and stand-related processes on treeline dynamics. In this study, we analyze the dynamics of four Pyrenean mountain pine treeline sites with contrasting stand structures, and subjected to differing rates of climate warming. Our models indicate that Pyrenean treelines could reach basal areas and reproductive potentials similar to those currently observed in high-elevation subalpine forest by the mid twenty-first century. The fastest paces of treeline densification are forecasted by the late twenty-first century and are associated with higher warming rates. We found a common densification response of Pyrenean treelines to climate warming, but contrasting paces arise due to current size structures. Treelines characterized by a multistratified stand structure and subjected to lower mean annual temperatures were the most responsive to climate warming. In monostratified stands, tree growth was less sensitive to temperature than in multistratified stands and trees reached their reproductive size threshold later. Therefore, our simulations highlight that stand structure is paramount in modulating treeline responsiveness to ongoing climate warming. Synthesis. Treeline densification over the twenty-first century is likely to occur at different rates contingent on current stand structure and its effects on individual-level tree growth responses to warming. Accurate projections of future treeline dynamics must thus incorporate site-specific factors other than climate, specifically those related to stand structure and its influence on tree growth. 相似文献
73.
Muñoz JA Chenoll E Casinos B Bataller E Ramón D Genovés S Montava R Ribes JM Buesa J Fàbrega J Rivero M 《Applied and environmental microbiology》2011,77(24):8775-8783
Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents. In this study, a novel Bifidobacterium longum subsp. infantis strain was isolated from infant feces and selected, based on its capacity to inhibit in vitro rotavirus Wa replication (up to 36.05% infectious foci reduction) and also to protect cells from virus infection (up to 48.50% infectious foci reduction) in both MA-104 and HT-29 cell lines. Furthermore, studies using a BALB/c mouse model have proved that this strain provides preliminary in vivo protection against rotavirus infection. The strain has been deposited in the Spanish Type Culture Collection under the accession number CECT 7210. This novel strain has the main properties required of a probiotic, such as resistance to gastrointestinal juices, biliary salts, NaCl, and low pH, as well as adhesion to intestinal mucus and sensitivity to antibiotics. The food safety status has been confirmed by the absence of undesirable metabolite production and in acute ingestion studies of mice. Overall, these results demonstrate that Bifidobacterium longum subsp. infantis CECT 7210 can be considered a probiotic able to inhibit rotavirus infection. 相似文献
74.
Soto S Alba A Ganges L Vidal E Raga JA Alegre F González B Medina P Zorrilla I Martínez J Marco A Pérez M Pérez B Pérez de Vargas Mesas A Martínez Valverde R Domingo M 《Diseases of aquatic organisms》2011,96(3):187-194
Dolphin morbillivirus (DMV) has caused 2 epizootics with high mortality rates on the Spanish Mediterranean coast, in 1990 and 2006-07, mainly affecting striped dolphins Stenella coeruleoalba. Following the first epizootic unusual DMV infections affecting only the central nervous system of striped dolphins were found, with histological features similar to subacute sclerosing panencephalitis and old dog encephalitis, the chronic latent localised infections caused by defective forms of measles virus and canine distemper virus, respectively. Between 2008 and 2010, monitoring by microscopic and immunohistochemical (IHC) studies of 118 striped dolphins stranded along Catalonia, the Valencia Region and Andalusia showed similar localised DMV nervous system infections in 25.0, 28.6 and 27.4% of cases, respectively, with no significant differences among regions or sex. The body length of DMV-infected dolphins was statistically greater than that of non-infected dolphins (196.5 vs. 160.5 cm; p < 0.001). Molecular detection of DMV was performed by 2 different RT-PCR techniques amplifying a 429 bp fragment and a 78 bp fragment both within the phosphoprotein (P) gene. The 429 bp RT-PCR results contradicted the IHC-DMV results as only 3 of 6 dolphins with positive IHC-DMV had positive PCR results. All 6 cases were positive with the 78 bp RT-PCR. These findings contraindicate the use of the 429 bp RT-PCR protocol based on the P gene to detect this specific form of DMV. DMV localised nervous infection constitutes the most relevant single cause of stranding and death in Mediterranean striped dolphins in the years following a DMV epizootic, and it might even overwhelm the effects of the epizootic itself, at least in 2007. 相似文献
75.
Castells E Molinier J Benvenuto G Bourbousse C Zabulon G Zalc A Cazzaniga S Genschik P Barneche F Bowler C 《The EMBO journal》2011,30(6):1162-1172
Plants and many other eukaryotes can make use of two major pathways to cope with mutagenic effects of light, photoreactivation and nucleotide excision repair (NER). While photoreactivation allows direct repair by photolyase enzymes using light energy, NER requires a stepwise mechanism with several protein complexes acting at the levels of lesion detection, DNA incision and resynthesis. Here we investigated the involvement in NER of DE-ETIOLATED 1 (DET1), an evolutionarily conserved factor that associates with components of the ubiquitylation machinery in plants and mammals and acts as a negative repressor of light-driven photomorphogenic development in Arabidopsis. Evidence is provided that plant DET1 acts with CULLIN4-based ubiquitin E3 ligase, and that appropriate dosage of DET1 protein is necessary for efficient removal of UV photoproducts through the NER pathway. Moreover, DET1 is required for CULLIN4-dependent targeted degradation of the UV-lesion recognition factor DDB2. Finally, DET1 protein is degraded concomitantly with DDB2 upon UV irradiation in a CUL4-dependent mechanism. Altogether, these data suggest that DET1 and DDB2 cooperate during the excision repair process. 相似文献
76.
Van Belle TL Esplugues E Liao J Juntti T Flavell RA von Herrath MG 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(6):2915-2922
Recent studies have shown that IL-17 can contribute beneficially to pathogen defense but also that excessive IL-17 levels are associated with chronic inflammation and autoimmune disorders. To date, the role of IL-17 in viral infections and type 1 diabetes is ambiguous. In this study, we used IL-17A enhanced green fluorescent protein bicistronic reporter mouse strains to analyze in situ production of IL-17A. Upon Klebsiella pneumoniae bacterial infection, CD4(+) and γδ T cells produce IL-17A. In contrast, CD4(+) or CD8(+) T cells do not produce IL-17A in response to acute or protracted viral infection with lymphocytic choriomeningitis virus or during autoimmune diabetes development in the CD8-driven lymphocytic choriomeningitis virus-induced model of type 1 diabetes. We conclude that viral elimination and type 1 diabetes can occur in the absence of detectable IL-17A production, suggesting IL-17A is not essential in these settings. 相似文献
77.
Joana F. Marques Hong-Lei Wang Glenn P. Svensson Enric Frago Olle Anderbrant 《Evolutionary ecology》2014,28(5):829-848
The brown tail moth (BTM) Euproctis chrysorrhoea (Linnaeus 1758) (Lepidoptera: Erebidae) is a forest and ornamental pest in Europe and the United States. Its extreme polyphagy, and documented phenological shift associated with host use suggest the presence of distinct host-races. To test this hypothesis, we sampled BTM infesting different host species in several locations along its distribution, and used DNA sequence data (a total of 1,672 bp from cytochrome c oxidase subunit I, elongation factor 1-alpha, and wingless) to produce haplotype networks and reconstruct the phylogenetic relationships between individuals. Population genetic diversity indices pointed out a higher genetic diversity in Europe, particularly in the samples from southern Spain and southern England. Lower F ST values were found between geographically closer populations when compared to more distant ones, but analyses of molecular variance and Mantel tests failed to reveal geographically associated genetic differentiation. However, haplotype networks and phylogenetic reconstructions revealed a previously unknown genetic differentiation within the BTM, with one lineage circumscribed to southern Europe. Although BTM haplotypes did not cluster according to their host plant, host-associated haplotypes were observed within certain geographic regions. Hence, our data support the existence of host-races of BTM within southern Spain and southern England, where populations from different hosts occur in sympatry. 相似文献
78.
Laura Lorenzo‐Orts Miguel Gonzalez‐Guzman Enric Sayas Jesús Muñoz‐Bertomeu Carla Ibañez Ramón Serrano Pedro L. Rodriguez 《The Plant journal : for cell and molecular biology》2014,80(6):1057-1071
Membrane‐delimited events play a crucial role for ABA signaling and PYR/PYL/RCAR ABA receptors, clade A PP2Cs and SnRK2/CPK kinases modulate the activity of different plasma membrane components involved in ABA action. Therefore, the turnover of PYR/PYL/RCARs in the proximity of plasma membrane might be a step that affects receptor function and downstream signaling. In this study we describe a single‐subunit RING‐type E3 ubiquitin ligase RSL1 that interacts with the PYL4 and PYR1 ABA receptors at the plasma membrane. Overexpression of RSL1 reduces ABA sensitivity and rsl1 RNAi lines that impair expression of several members of the RSL1/RFA gene family show enhanced sensitivity to ABA. RSL1 bears a C‐terminal transmembrane domain that targets the E3 ligase to plasma membrane. Accordingly, bimolecular fluorescent complementation (BiFC) studies showed the RSL1–PYL4 and RSL1–PYR1 interaction is localized to plasma membrane. RSL1 promoted PYL4 and PYR1 degradation in vivo and mediated in vitro ubiquitylation of the receptors. Taken together, these results suggest ubiquitylation of ABA receptors at plasma membrane is a process that might affect their function via effect on their half‐life, protein interactions or trafficking. 相似文献
79.
80.
Paolo Guidetti Pasquale Baiata Enric Ballesteros Antonio Di Franco Bernat Hereu Enrique Macpherson Fiorenza Micheli Antonio Pais Pieraugusto Panzalis Andrew A. Rosenberg Mikel Zabala Enric Sala 《PloS one》2014,9(4)
Marine protected areas (MPAs) were acknowledged globally as effective tools to mitigate the threats to oceans caused by fishing. Several studies assessed the effectiveness of individual MPAs in protecting fish assemblages, but regional assessments of multiple MPAs are scarce. Moreover, empirical evidence on the role of MPAs in contrasting the propagation of non-indigenous-species (NIS) and thermophilic species (ThS) is missing. We simultaneously investigated here the role of MPAs in reversing the effects of overfishing and in limiting the spread of NIS and ThS. The Mediterranean Sea was selected as study area as it is a region where 1) MPAs are numerous, 2) fishing has affected species and ecosystems, and 3) the arrival of NIS and the northward expansion of ThS took place. Fish surveys were done in well-enforced no-take MPAs (HP), partially-protected MPAs (IP) and fished areas (F) at 30 locations across the Mediterranean. Significantly higher fish biomass was found in HP compared to IP MPAs and F. Along a recovery trajectory from F to HP MPAs, IP were similar to F, showing that just well enforced MPAs triggers an effective recovery. Within HP MPAs, trophic structure of fish assemblages resembled a top-heavy biomass pyramid. Although the functional structure of fish assemblages was consistent among HP MPAs, species driving the recovery in HP MPAs differed among locations: this suggests that the recovery trajectories in HP MPAs are likely to be functionally similar (i.e., represented by predictable changes in trophic groups, especially fish predators), but the specific composition of the resulting assemblages may depend on local conditions. Our study did not show any effect of MPAs on NIS and ThS. These results may help provide more robust expectations, at proper regional scale, about the effects of new MPAs that may be established in the Mediterranean Sea and other ecoregions worldwide. 相似文献