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1.
In vitro dephosphorylation inhibits the activity of soybean lysine-ketoglutarate reductase in a lysine-regulated manner 总被引:2,自引:0,他引:2
Daphna Miron Sari Ben-Yaacov Hagai Karchi Gad Galili 《The Plant journal : for cell and molecular biology》1997,12(6):1453-1458
In plant seeds, the essential amino acid lysine auto-regulates its own level by modulating the activity of its catabolic enzyme lysine-ketoglutarate reductase via an intracellular signaling cascade, mediated by Ca2+ and protein phosphorylation/dephosphorylation. In the present report, it has been further tested whether the activity of soybean lysine-ketoglutarate reductase, as well as that of saccharopine dehydrogenase, the second enzyme in the pathway of lysine catabolism, are modulated by direct phosphorylation of the bifunctional polypeptide containing both of these linked activities. Incubation of purified lysine-ketoglutarate reductase/ saccharopine dehydrogenase with casein kinase II resulted in a significant phosphorylation of the bifunctional enzyme. Moreover, in vitro dephosphorylation of the bifunctional polypeptide with alkaline phosphatase significantly inhibited the activity of lysine-ketoglutarate reductase, but not of its linked enzyme saccharopine dehydrogenase. The inhibitory effect of alkaline phosphatase on lysine-ketoglutarate reductase activity was dramatically stimulated by binding of lysine to the enzyme. Our results suggest that in plant seeds, active lysine-ketoglutarate reductase is a phospho-protein, and that its activity is modulated by opposing actions of protein kinases and phosphatases. Moreover, this modulation is subject to a compound regulation by lysine. 相似文献
2.
Kate M. Scott Karestan C. Koenen Sergio Aguilar-Gaxiola Jordi Alonso Matthias C. Angermeyer Corina Benjet Ronny Bruffaerts Jose Miguel Caldas-de-Almeida Giovanni de Girolamo Silvia Florescu Noboru Iwata Daphna Levinson Carmen C. W. Lim Sam Murphy Johan Ormel Jose Posada-Villa Ronald C. Kessler 《PloS one》2013,8(11)
Background
Associations between lifetime traumatic event (LTE) exposures and subsequent physical ill-health are well established but it has remained unclear whether these are explained by PTSD or other mental disorders. This study examined this question and investigated whether associations varied by type and number of LTEs, across physical condition outcomes, or across countries.Methods
Cross-sectional, face-to-face household surveys of adults (18+) were conducted in 14 countries (n = 38, 051). The Composite International Diagnostic Interview assessed lifetime LTEs and DSM-IV mental disorders. Chronic physical conditions were ascertained by self-report of physician''s diagnosis and year of diagnosis or onset. Survival analyses estimated associations between the number and type of LTEs with the subsequent onset of 11 physical conditions, with and without adjustment for mental disorders.Findings
A dose-response association was found between increasing number of LTEs and odds of any physical condition onset (OR 1.5 [95% CI: 1.4–1.5] for 1 LTE; 2.1 [2.0–2.3] for 5+ LTEs), independent of all mental disorders. Associations did not vary greatly by type of LTE (except for combat and other war experience), nor across countries. A history of 1 LTE was associated with 7/11 of the physical conditions (ORs 1.3 [1.2–1.5] to 1.7 [1.4–2.0]) and a history of 5+ LTEs was associated with 9/11 physical conditions (ORs 1.8 [1.3–2.4] to 3.6 [2.0–6.5]), the exceptions being cancer and stroke.Conclusions
Traumatic events are associated with adverse downstream effects on physical health, independent of PTSD and other mental disorders. Although the associations are modest they have public health implications due to the high prevalence of traumatic events and the range of common physical conditions affected. The effects of traumatic stress are a concern for all medical professionals and researchers, not just mental health specialists. 相似文献3.
Podstolski A Havkin-Frenkel D Malinowski J Blount JW Kourteva G Dixon RA 《Phytochemistry》2002,61(6):611-620
Tissue cultures of the vanilla orchid, Vanilla planifolia, produce the flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde) and vanillin precursors such as 4-hydroxybenzaldehyde. A constitutively expressed enzyme activity catalyzing chain shortening of a hydroxycinnamic acid, believed to be the first reaction specific for formation of vanilla flavor compounds, was identified in these cultures. The enzyme converts 4-coumaric acid non-oxidatively to 4-hydroxybenzaldehyde in the presence of a thiol reagent but with no co-factor requirement. Several forms of this 4-hydroxybenzaldehyde synthase (4HBS) were resolved and partially purified by a combination of hydrophobic interaction, ion exchange and gel filtration chromatography. These forms appear to be interconvertible. The unusual properties of the 4HBS, and its appearance in different protein fractions, raise questions as to its physiological role in vanillin biosynthesis in vivo. 相似文献
4.
Prim de Bie Daphna Zaaroor-Regev Aaron Ciechanover 《Biochemical and biophysical research communications》2010,400(3):389-395
The E3 ubiquitin ligase RING1B plays an important role in Polycomb-mediated gene silencing by monoubiquitinating histone H2A. Both the activity and stability of RING1B are controlled by ubiquitination in two distinct manners. Self ubiquitination of RING1B generates K6, K27 and K48-based mixed polyubiquitin chain, and is required for its activity as a ligase. On the other hand, its proteasomal degradation is mediated by another ligase; E6-AP catalyzes the formation of K48-based chains. Since these two modes of ubiquitination target the same lysine residues and are therefore mutually exclusive, an important mode of regulation of RING1B should be at the level of deubiquitination. Here we identify USP7 as a deubiquitinating enzyme that regulates the ubiquitination state of RING1B. RING1B interacts with USP7, which is mediated in part by its RING domain. In addition, USP7 was found in a complex with other Polycomb proteins, suggesting a broad role in regulating these complexes. Although, USP7 directly and specifically deubiquitinates RING1B in vitro and in vivo, it does not discriminate between the activating and proteolysis-targeting modes of ubiquitination, and therefore has a stabilizing effect on RING1B. 相似文献
5.
Daphna Birenbaum-Carmeli 《Medical anthropology quarterly》2001,15(4):556-558
What Makes Women Sick: Maternity, Modesty and Militarism in Israeli Society. Susan Sered. Hanover and London: Brandeis University Press, 2000. + 194 pp. 相似文献
6.
Shohamy D 《Current opinion in neurobiology》2011,21(3):408-414
The past decade has seen a dramatic change in our understanding of the role of the striatum in behavior. Early perspectives emphasized a role for the striatum in habitual learning of stimulus-response associations and sequences of actions. Recent advances from human neuroimaging research suggest a broader role for the striatum in motivated learning. New findings demonstrate that the striatum represents multiple learning signals and highlight the contribution of the striatum across many cognitive domains and contexts. Recent findings also emphasize interactions between the striatum and other specialized brain systems for learning. Together, these findings suggest that the striatum contributes to a distributed network that learns to select actions based on their predicted value in order to optimize behavior. 相似文献
7.
An identical miRNA of the human JC and BK polyoma viruses targets the stress-induced ligand ULBP3 to escape immune elimination 总被引:1,自引:0,他引:1
Bauman Y Nachmani D Vitenshtein A Tsukerman P Drayman N Stern-Ginossar N Lankry D Gruda R Mandelboim O 《Cell host & microbe》2011,9(2):93-102
The human polyoma viruses JCV and BKV establish asymptomatic persistent infection in 65%-90% of humans but can cause severe illness under immunosuppressive conditions. The mechanisms by which these viruses evade immune recognition are unknown. Here we show that a viral miRNA identical in sequence between JCV and BKV targets the stress-induced ligand ULBP3, which is a protein recognized by the killer receptor NKG2D. Consequently, viral miRNA-mediated ULBP3 downregulation results in reduced NKG2D-mediated killing of virus-infected cells by natural killer (NK) cells. Importantly, when the activity of the viral miRNA was inhibited during infection, NK cells killed the infected cells more efficiently. Because NKG2D is also expressed by various T cell subsets, we propose that JCV and BKV use an identical miRNA that targets ULBP3 to escape detection by both the innate and adaptive immune systems, explaining how these viruses remain latent without being eliminated by the immune system. 相似文献
8.
Litinsky I Paran D Levartovsky D Wigler I Kaufman I Yaron I Yaron M Caspi D Elkayam O 《Cytokine》2006,33(2):106-110
OBJECTIVE: The purpose of this open pilot study was to assess possible mechanisms of the effects of leflunomide by studying the influence of the drug on the serum levels of MMP-1, MMP-3, IL-10, IL-6 and their possible correlation with clinical disease parameters. PATIENTS AND METHODS: Thirty patients with long standing active rheumatoid arthritis were enrolled in this study. All patients failed at least 5 DMARDs in the past and were on stable treatment for at least 3 months before starting the protocol. The patients received a loading dose of 100 mg for 3 days followed by 20 mg/day thereafter and followed up monthly for 6 months. Disease activity was assessed at baseline, 2 weeks, and every month of therapy thereafter using the following variables: tender joint count, swollen joint count, morning stiffness duration, pain, tiredness, physician's and patient's global assessment, using VAS, ESR and CRP. Clinical effects of the treatment regimen were calculated using the American College of Rheumatology (ACR) criteria for clinical response. Adverse events were recorded. Serum levels of MMP-1, MMP-3, IL-10 and IL-6 were measured before and 3 months after starting the protocol. RESULTS: Except for tiredness, a statistically significant improvement in all clinical and laboratory parameters of disease activity was reached after 3 months. At this time point the ACR-20 response rate was 46.2%. The levels of MMP-1, MMP-3, IL-6 and IL-10 decreased significantly after 3 months. A statistically significant correlation between serum levels of MMP-1, IL-10 and IL-6 and clinical and laboratory parameters was also shown. After 6 months, 16 out of 30 patients withdrew from the study [adverse events (35.4%), lack of efficacy (9.7%), and low compliance (6.4%)]. CONCLUSIONS: Leflunomide was clinically efficacious in this group of long standing resistant RA in an open study "real life" design. These results comply with those reported in previous clinical trials. Serum MMP-1, MMP-3, IL-10 and IL-6 levels decreased significantly. Despite high withdrawal rate, no serious adverse effects were recorded. 相似文献
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10.
Lev A Simon AJ Bareket M Bielorai B Hutt D Amariglio N Rechavi G Somech R 《PloS one》2012,7(1):e30494
The kinetics of T and B cell immune recovery after bone marrow transplantation (BMT) is affected by many pre- and post-transplant factors. Because of the profoundly depleted baseline T and B cell immunity in recombination activating gene 2 (RAG-2)-deficient severe combined immunodeficiency (SCID) patients, some of these factors are eliminated, and the immune recovery after BMT can then be clearly assessed. This process was followed in ten SCID patients in parallel to their associated transplant-related complications. Early peripheral presence of T and B cells was observed in 8 and 4 patients, respectively. The latter correlated with pre-transplant conditioning therapy. Cells from these patients carried mainly signal joint DNA episomes, indicative of newly derived B and T cells. They were present before the normalization of the T cell receptor (TCR) and the B cell receptor (BCR) repertoire. Early presentation of the ordered TCR gene rearrangements after BMT occurred simultaneously, but this pattern was heterogeneous over time, suggesting different and individual thymic recovery processes. Our findings early after transplant could suggest the long-term patients' clinical outcome. Early peripheral presence of newly produced B and T lymphocytes from their production and maturation sites after BMT suggests donor stem cell origin rather than peripheral expansion, and is indicative of successful outcome. Peripheral detection of TCR excision circles and kappa-deleting recombination excision circles in RAG-2-deficient SCID post-BMT are early markers of T and B cell reconstitution, and can be used to monitor outcome and tailor specific therapy for patients undergoing BMT. 相似文献