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101.
Mor I Bruck T Greenberg D Berson A Schreiber L Grisaru D Soreq H 《Chemico-biological interactions》2008,175(1-3):11-21
Tumorogenic transformation is a multifaceted cellular process involving combinatorial protein-protein interactions that modulate different cellular functions. Here, we report apparent involvement in two independent tumorogenic processes by distinct partner protein interactions of the stress-induced acetylcholinesterase AChE-R and N-AChE-R variants. Human testicular tumors showed elevated levels of N-terminally extended N-AChE-R compared with healthy tissue, indicating alternate promoter usage in the transformed cells. Two-hybrid screens demonstrate that the C-terminus common to both N-AChE-R and AChE-R interacts either with the glycolytic enzyme enolase or with the scaffold protein RACK1. In vitro, the AChE-R C-terminal peptide ARP elevated enolase's activity by 12%, suggesting physiological relevance for this interaction. Correspondingly, CHO cells expressing either human AChE-R or N-AChE-R but not AChE-S showed a 25% increase in cellular ATP levels, indicating metabolic significance for this upregulation of enolase activity. ATP levels could be reduced by AChE-targeted siRNA in CHO cells expressing AChE-R but not AChE-S, attributing this elevation to the AChE-R C-terminus. Additionally, transfected CHO cells expressing AChE-R but not N-AChE-R showed resistance to up to 60muM of the common chemotherapeutic agent, cis-platinum, indicating AChE-R involvement in another molecular pathway. cis-Platinum elevates the expression of the apoptosis-regulator p53-like protein, p73, which is inactivated by interaction with the scaffold protein RACK1. In co-transfected cells, AChE-R competed with endogenous RACK1 for p73 interaction. Moreover, AChE-R-transfected CHO cells presented higher levels than control cells of the pro-apoptotic TAp73 as well as the anti-apoptotic dominant negative DeltaNp73 protein, leading to an overall decrease in the proportion of pro-apoptotic p73. Together, these findings are compatible with the hypothesis that in cancer cells, both AChE-R and N-AChE-R elevate cellular ATP levels and that AChE-R modifies p73 gene expression by facilitating two independent cellular pathways, thus conferring both a selective metabolic advantage and a genotoxic resistance. 相似文献
102.
Spinach (Spinacia oleracea L. cv. Clermont) leaves grown in open-top chambers and exposed to three different concentrations of ozone were measured for gas exchange, chlorophyll a fluorescence, antioxidant systems, and lipid peroxidation at the end of growing season. High O3 concentration reduced Fv/Fm, indicating that the efficiency in the energy conversion of photosystem 2 (PS2) was altered. The rate of non-cyclic electron transport rate and the capacity to reduce the quinone pool were also affected. The development of non-photochemical quenching was not high enough to decrease the photon excess in the PS2. The limitation of photosynthetic activity was probably correlated with stomata closure and with an increase in intercellular CO2 concentration. Under oxidative stress, superoxide dismutase (SOD) activity was stimulated in parallel with lipid peroxidation. We did not find any differences in the ascorbate (AsA) pool and ascorbate peroxidase (APX) or glutathione reductase (GR) activities between air qualities. Small, but similar responses were observed in spinach leaves exposed to ambient ozone concentration. 相似文献
103.
Moshe Tal 《In vitro cellular & developmental biology. Plant》1994,30(4):175-180
Summary In recent years attempts have been made to supplement traditional breeding for the production of salt-tolerant plants with
variability existing in cell culture. The potential causes suggested as an explanation for the limited success of the in vitro
approach include: a) lack, or loss during selection, of regeneration capability; b) the development of epigenetically adapted
cells; c) lack of correlation between the mechanisms of tolerance operating in cultured cells and mechanisms that operate
in cells in the intact plant; and d) multigenicity of salt tolerance. The recent successful production of healthy, fertile,
and genetically stable salt-tolerant regenerants from cells obtained from highly morphogenic explants which are selected early
in culture (using one-step or short-term strategies) for salt tolerance, together with the demonstration that salt-sensitive
plants can become tolerant by mutations in one or few genes, suggest that some of the potential limitations can be overcome
and that some of them may not exist at all. 相似文献
104.
Background
Detecting candidate B-cell epitopes in a protein is a basic and fundamental step in many immunological applications. Due to the impracticality of experimental approaches to systematically scan the entire protein, a computational tool that predicts the most probable epitope regions is desirable. 相似文献105.
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108.
Localization of the Gene for Thiamine-Responsive Megaloblastic Anemia Syndrome, on the Long Arm of Chromosome 1, by Homozygosity Mapping 总被引:5,自引:0,他引:5 下载免费PDF全文
Ellis J. Neufeld Hanna Mandel Tal Raz Raymonde Szargel Chandri N. Yandava Amy Stagg Sabine Fauré Timothy Barrett Neil Buist Nadine Cohen 《American journal of human genetics》1997,61(6):1335-1341
Thiamine-responsive megaloblastic anemia, also known as "TRMA" or "Rogers syndrome," is an early-onset autosomal recessive disorder defined by the occurrence of megaloblastic anemia, diabetes mellitus, and sensorineural deafness, responding in varying degrees to thiamine treatment. On the basis of a linkage analysis of affected families of Alaskan and of Italian origin, we found, using homozygosity mapping, that the TRMA-syndrome gene maps to a region on chromosome 1q23.2-23.3 (maximum LOD score of 3.7 for D1S1679). By use of additional consanguineous kindreds of Israeli-Arab origin, the putative disease-gene interval also has been confirmed and narrowed, suggesting genetic homogeneity. Linkage analysis generated the highest combined LOD-score value, 8.1 at a recombination fraction of 0, with marker D1S2799. Haplotype analysis and recombination events narrowed the TRMA locus to a 16-cM region between markers D1S194 and D1S2786. Several heterozygote parents had diabetes mellitus, deafness, or megaloblastic anemia, which raised the possibility that mutations at this locus predispose carriers in general to these manifestations. Characterization of the metabolic defect of TRMA may shed light on the role of thiamine deficiency in such common diseases. 相似文献
109.
F. G. Sulman A. Danon Y. Pfeifer E. Tal C. P. Weller 《International journal of biometeorology》1970,14(1):45-53
Hot dry winds (Sharav in Israel) are notorious for causing controversial symptoms such as depression, discomfort, headaches, irritability and exacerbation of respiratory ailments. Daily urinalysis combined with study of the complaints of two hundred weather-sensitive patients suffering from Sharav have shown that there exist at least three different patterns of reaction: serotonin hypersecretion causing a general "Irritation Syndrome", catecholamine deficiency resulting in the "Exhaustion Syndrome", histamine and creatinine overproduction combined with clinical "Hyperthyroidism - Forme Fruste" and typical thyroid complaints. These syndromes are amenable to appropriate treatment controlled by urinalysis.
Zusammenfassung Trockene heisse Wüstenwinde (Sharav in Israel) rufen eine seltsame Mischung von Symptomen hervor wie Depression, Unwohlsein, Kopfschmerzen, Reizbarkeit und Verschlimmerung respiratorischer Beschwerden. Tägliche Urinuntersuchungen kombiniert mit dem Studium der verschiedenen Beschwerden von 200 Sharav-gefühligen Personen haben gezeigt, dass drei verschiedene Reaktionsformen vorliegen: Serotonin-Ausschüttung, die zu einem allgemeinen Irritationssyndrom führt; Katecholamin-Mangel, der zu einem typischen Erschöpfungssyndrom führt; Histamin- und Kreatinin-Ausschüttung, die mit leichtem Hyperthyreoidismus einhergehen. Letzteres Syndrom bereitet dem Patienten nur an Sharav-Tagen Beschwerden. Die Syndrome sind durch gezielte und Urin-kontrollierte Behandlung heilbar.
Resume Des vents chauds et secs provenant du désert (le Charav en Israël par exemple) sont connus pour provoquer un ensemble de symptômes particuliers tels que dépression nerveuse, indisposition, céphalées, irritabilité et aggravation des troubles respiratoires. L'analyse journalière de l'urine et l'étude des divers symptômes que présentaient 200 personnes sensibles au Charav ont montré la présence de trois formes différentes de réactions: sécrétion accrue de sérotonine qui conduit à un syndrome d'irritabilité générale; une carence en catécholamine qui se traduit par un syndrome typique d'épuisement; une sécrétion d'histamine et de créatinine parallèle à un faible hyperthyréoïdisme. Ce dernier syndrome ne provoque des troubles aux patients que durant les jours où le Charav souffle. Ces trois syndromes sont guérissables par une médication appropriée et dont l'effet est contrôlé par des analyses d'urine.相似文献
110.