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31.
Saito N Courtois G Chiba A Yamamoto N Nitta T Hironaka N Rowe M Yamamoto N Yamaoka S 《The Journal of biological chemistry》2003,278(47):46565-46575
Latent membrane protein 1 (LMP1), an Epstein-Barr virus transforming protein, is able to activate NF-kappaB through its carboxyl-terminal activation region 1 (CTAR1) and 2 (CTAR2), but the exact role of each domain is not fully understood. Here we show that LMP1 activates NF-kappaB in different NF-kappaB essential modulator (NEMO)-defective cell lines, but not in cells lacking both IkappaB kinase 1 (IKK1) and 2 (IKK2). Mutational studies reveal that CTAR1, but not CTAR2, mediates NEMO-independent NF-kappaB activation and that this process largely depends on IKK1. Retroviral expression of LMP1 mutants in cells lacking either functional NF-kappaB inducing kinase (NIK), NEMO, IKK1, or IKK2 further illustrates distinct signals from the two activation regions of LMP1 for persistent NF-kappaB activation. One originates in CTAR2, operates through the canonical NEMO-dependent pathway, and induces NFKB2 p100 production; the second signal originates in CTAR1, utilizes NIK and IKK1, and induces the processing of p100. Our results thus help clarify how two functional domains of LMP1 persistently activate NF-kappaB through distinct signaling pathways. 相似文献
32.
The drug efflux pump MRP2: regulation of expression in physiopathological situations and by endogenous and exogenous compounds 总被引:3,自引:0,他引:3
Payen L Sparfel L Courtois A Vernhet L Guillouzo A Fardel O 《Cell biology and toxicology》2002,18(4):221-233
The multidrug resistance-associated protein 2 (MRP2) is an ATP-binding cassette transporter involved in biliary, renal, and
intestinal secretion of numerous organic anions, including endogenous compounds such as bilirubin and exogenous compounds
such as drugs and toxic chemicals. Its expression can be modulated in various physiopathological situations, notably being
markedly decreased during liver cholestasis and upregulated in some cancerous tissues. In addition, MRP2 levels are altered
in hepatocytes in response to hormones such as glucocorticoids and to structurally unrelated drugs such as rifampicin, phenobarbital,
ritonavir, and cisplatin. The chemical carcinogen 2-acetylaminofluorene and chemopreventive agents such as oltipraz and sulforaphane
also markedly increased MRP2 expression in liver parenchymal cells. Interestingly, most of the chemical inducers of MRP2 act
on drug-metabolizing enzymes, indicating a coordinated regulation of these detoxifying proteins; cellular mechanisms involved
are, at least partly, common and may be related to nuclear hormone receptors such as the pregnane X receptor. Owing to the
major role played by MRP2 in elimination of drugs and endogenous compounds, modulation of its expression may lead to adverse
effects or to changes in drug pharmacokinetics.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
33.
Plasma membrane aquaporins are involved in winter embolism recovery in walnut tree 总被引:7,自引:0,他引:7 下载免费PDF全文
Sakr S Alves G Morillon R Maurel K Decourteix M Guilliot A Fleurat-Lessard P Julien JL Chrispeels MJ 《Plant physiology》2003,133(2):630-641
In perennial plants, freeze-thaw cycles during the winter months can induce the formation of air bubbles in xylem vessels, leading to changes in their hydraulic conductivity. Refilling of embolized xylem vessels requires an osmotic force that is created by the accumulation of soluble sugars in the vessels. Low water potential leads to water movement from the parenchyma cells into the xylem vessels. The water flux gives rise to a positive pressure essential for the recovery of xylem hydraulic conductivity. We investigated the possible role of plasma membrane aquaporins in winter embolism recovery in walnut (Juglans regia). First, we established that xylem parenchyma starch is converted to sucrose in the winter months. Then, from a xylem-derived cDNA library, we isolated two PIP2 aquaporin genes (JrPIP2,1 and JrPIP2,2) that encode nearly identical proteins. The water channel activity of the JrPIP2,1 protein was demonstrated by its expression in Xenopus laevis oocytes. The expression of the two PIP2 isoforms was investigated throughout the autumn-winter period. In the winter period, high levels of PIP2 mRNA and corresponding protein occurred simultaneously with the rise in sucrose. Furthermore, immunolocalization studies in the winter period show that PIP2 aquaporins were mainly localized in vessel-associated cells, which play a major role in controlling solute flux between parenchyma cells and xylem vessels. Taken together, our data suggest that PIP2 aquaporins could play a role in water transport between xylem parenchyma cells and embolized vessels. 相似文献
34.
Identification of QTL for growth- and grain yield-related traits in rice across nine locations of Asia 总被引:19,自引:0,他引:19
Hittalmani S Huang N Courtois B Venuprasad R Shashidhar HE Zhuang JY Zheng KL Liu GF Wang GC Sidhu JS Srivantaneeyakul S Singh VP Bagali PG Prasanna HC McLaren G Khush GS 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(4):679-690
Rice double-haploid (DH) lines of an indica and japonica cross were grown at nine different locations across four countries in Asia. Genotype-by-environment (G x E) interaction analysis for 11 growth- and grain yield-related traits in nine locations was estimated by AMMI analysis. Maximum G x E interaction was exhibited for fertility percentage number of spikelets and grain yield. Plant height was least affected by environment, and the AMMI model explained a total of 76.2% of the interaction effect. Mean environment was computed by averaging the nine environments and subsequently analyzed with other environments to map quantitative trait loci (QTL). QTL controlling the 11 traits were detected by interval analysis using mapmaker/qtl. A threshold LOD of >/=3.20 was used to identify significant QTL. A total of 126 QTL were identified for the 11 traits across nine locations. Thirty-four QTL common in more than one environment were identified on ten chromosomes. A maximum of 44 QTL were detected for panicle length, and the maximum number of common QTL were detected for days to heading detected. A single locus for plant height (RZ730-RG810) had QTL common in all ten environments, confirming AMMI results that QTL for plant height were affected the least by environment, indicating the stability of the trait. Two QTL were detected for grain yield and 19 for thousand-grain weight in all DH lines. The number of QTL per trait per location ranged from zero to four. Clustering of the QTL for different traits at the same marker intervals was observed for plant height, panicle number, panicle length and spikelet number suggesting that pleiotropism and or tight linkage of different traits could be the possible reason for the congruence of several QTL. The many QTL detected by the same marker interval across environments indicate that QTL for most traits are stable and not essentially affected by environmental factors. 相似文献
35.
Oswald IP Desautels C Laffitte J Fournout S Peres SY Odin M Le Bars P Le Bars J Fairbrother JM 《Applied and environmental microbiology》2003,69(10):5870-5874
Fumonisin B(1) (FB(1)) is a mycotoxin that commonly occurs in maize. FB(1) causes a variety of toxic effects in different animal species and has been implicated as a contributing factor of esophageal cancers in humans. In the present study, we examined the effect of dietary exposure to FB(1) on intestinal colonization by pathogenic Escherichia coli associated with extraintestinal infection. Three-week-old weaned pigs were given FB(1) by gavage as a crude extract or as a purified toxin at a dose of 0.5 mg/kg of body weight daily for 6 days. On the last day of the toxin treatment, the pigs were orally inoculated with an extraintestinal pathogenic E. coli strain. All animals were euthanized 24 h later, necropsies were performed, and tissues were taken for bacterial counts and light microscopic examination. Ingestion of FB(1) had only a minimal effect on animal weight gain, did not cause any macroscopic or microscopic lesions, and did not change the plasma biochemical profile. However, colonization of the small and large intestines by an extraintestinal pathogenic E. coli strain was significantly increased. Our results show that FB(1) is a predisposing factor to infectious disease and that the pig can be used as a model for the study of the consequences of ingesting mycotoxin-contaminated food. 相似文献
36.
37.
Ducret T El Arrouchi J Courtois A Quignard JF Marthan R Savineau JP 《Cell calcium》2010,48(5):251-259
Stretch-activated channels (SACs) act as membrane mechanotransducers since they convert physical forces into biological signals and hence into a cell response. Pulmonary arterial smooth muscle cells (PASMCs) are continuously exposed to mechanical stimulations e.g., compression and stretch, that are enhanced under conditions of pulmonary arterial hypertension (PAH). Using the patch-clamp technique (cell-attached configuration) in PASMCs, we showed that applying graded negative pressures (from 0 to -60 mmHg) to the back end of the patch pipette increases occurrence and activity of SACs. The current-voltage relationship (from -80 to +40 mV) was almost linear with a reversal potential of 1 mV and a slope conductance of 34 pS. SACs were inhibited in the presence of GsMTx-4, a specific SACs blocker. Using microspectrofluorimetry (indo-1), we found that hypotonic-induced cell swelling increases intracellular Ca(2+) concentration ([Ca(2+)](i)). This [Ca(2+)](i) increase was markedly inhibited in the absence of external Ca(2+) or in the presence of the following blockers of SACs: gadolinium, streptomycin, and GsMTx-4. Interestingly, in chronically hypoxic rats, an animal model of PAH, SACs were more active and hypotonic-induced calcium response in PASMCs was significantly higher (nearly a two-fold increase). Moreover, unlike in normoxic rats, intrapulmonary artery rings from hypoxic rats mounted in a Mulvany myograph, exhibited a myogenic tone sensitive to SAC blockers. In conclusion, this work demonstrates that SACs in rat PASMCs can be activated by membrane stretch as well as hypotonic stimulation and are responsible for [Ca(2+)](i) increase. The link between SACs activation-induced calcium response and myogenic tone in chronically hypoxic rats suggests that SACs are an important element for the increased pulmonary vascular tone in PAH and that they may represent a molecular target for PAH treatment. 相似文献
38.
Structure, allelic diversity and selection of Asr genes, candidate for drought tolerance, in Oryza sativa L. and wild relatives 总被引:1,自引:0,他引:1
39.
Isabelle Peubez Nicolas Chaudet Charlotte Mignon Géraldine Hild Stéphanie Husson Virginie Courtois Karelle De Luca Denis Speck Régis Sodoyer 《Microbial cell factories》2010,9(1):65
Background
The increasing regulatory requirements to which biological agents are subjected will have a great impact in the field of industrial protein expression and production. There is an expectation that in a near future, there may be "zero tolerance" towards antibiotic-based selection and production systems. Besides the antibiotic itself, the antibiotic resistance gene is an important consideration. The complete absence of antibiotic-resistance gene being the only way to ensure that there is no propagation in the environment or transfer of resistance to pathogenic strains. 相似文献40.
Marcano M Pugh T Cros E Morales S Portillo Páez EA Courtois B Glaszmann JC Engels JM Phillips W Astorga C Risterucci AM Fouet O González V Rosenberg K Vallat I Dagert M Lanaud C 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(5):877-884
A sound understanding of crop history can provide the basis for deriving novel genetic information through admixture mapping.
We confirmed this, by using characterization data from an international collection of cocoa, collected 25 years ago, and from
a contemporary plantation. We focus on the trees derived from three centuries of admixture between Meso-American Criollo and
South American Forastero genomes. In both cacao sets of individuals, linkage disequilibrium extended over long genetic distances
along chromosome regions, as expected in populations derived from recent admixture. Based on loose genome scans, genomic regions
involved in useful traits were identified. Fifteen genomic regions involved in seed and fruit weight variation were highlighted.
They correspond to ten previously identified QTLs and five novel ones. Admixture mapping can help to add value to genetic
resources and thus, help to encourage investment in their conservation.
Maria Marcano and Tatiana Pugh contributed equally to this work. 相似文献