Search results for "PHOSPHATASE"
showing 10 items of 499 documents
8-Azido-adenosine 5'-triphosphate as a Photoaffinity Label for Bacterial F1 ATPase
1978
1. 8-Azido-adenosine 5'-triphosphate (n83ATP) is a suitable photoaffinity label for F1 ATPase from Micrococcus luteus. The nucleotide is a substrate in the presence of bivalent cations and inhibits the enzyme irreversibly upon irradiation with ultraviolet light above 300 nm. 2. More than 80% of the label is covalently bound to the beta subunits in the presence of bivalent cations. Labeling and inactivation is decreased by protection with ADP, ATP or adenyl-5'-yl imidodiphosphate. To a much smaller degree the alpha subunits also become labeled. 3. n83AMP does not specifically bind to the beta subunits upon irradiation. Like n83ATP and n83ADP, it also labels the alpha subunits to a small exte…
Identification of the phosphoglycerate dehydrogenase isoform EDA9 as the essential gene for embryo and male gametophyte development in Arabidopsis
2013
[EN] Three different pathways of serine (Ser) biosynthesis have been described in plants: the Glycolate pathway, which is part of the Photorespiratory pathway, and 2 non-Photorespiratory pathways, the Glycerate and the Phosphorylated pathways. The Phosphorylated Pathway of Ser Biosynthesis (PPSB) has been known to exist since the 1950s, but its biological relevance was not revealed until quite recently when the last enzyme of the pathway, the Phosphoserine Phosphatase, was functionally characterized. In the associated study1, we characterized a family of genes coding for putatite phosphoglycerate dehydrogenases (PGDH, 3-PGDH, and EDA9), the first enzyme of the PPSB. A metabolomics study usi…
The essential role of the phosphorylated pathway of serine biosynthesis inArabidopsis
2013
[EN] In plants, 3 different pathways of serine biosynthesis have been described: the Glycolate pathway, which is associated with photorespiration, and 2 non-photorespiratory pathways, the Glycerate and the Phosphorylated pathways. The Phosphorylated Pathway of Serine Biosynthesis (PPSB) has been known since the 1950s, but has been studied relatively little, probably because it was considered of minor significance as compared with the Glycolate pathway. In the associated study1 , we described for the first time in plants the in vivo functional characterization of the PPSB, by targeting the phosphoserine phosphatase (PSP1), the last enzyme of the pathway. Following a gain—and loss-of-function…
Pancreatic Protein Tyrosine Phosphatase 1B Deficiency Exacerbates Acute Pancreatitis in Mice
2016
Acute pancreatitis (AP) is a common and devastating gastrointestinal disorder that causes significant morbidity. The disease starts as local inflammation in the pancreas that may progress to systemic inflammation and complications. Protein tyrosine phosphatase 1B (PTP1B) is implicated in inflammatory signaling, but its significance in AP remains unclear. To investigate whether PTP1B may have a role in AP, we used pancreas PTP1B knockout (panc-PTP1B KO) mice and determined the effects of pancreatic PTP1B deficiency on cerulein- and arginine-induced acute pancreatitis. We report that PTP1B protein expression was increased in the early phase of AP in mice and rats. In addition, histological an…
SARS CoV2 infection _The longevity study perspectives
2021
Graphical abstract
Associations between atopic diseases and the polymorphic systems ABO, Kidd, Inv and red cell acid phosphatase.
1979
In 239 German patients with atopic conditions (atopic dermatitis, hay fever, allergic rhinitis, bronchial asthma, and acute urticaria) the phenotype and gene distribution of 15 genetic blood polymorphisms (ABO, MNSs, rhesus, P, Kell, Duffy, Kidd, Hp, Gc, Gm, Inv, aP, PGM1, EsD, and 6-PGD) were analyzed and compared with those in 151 selected controls (individuals clinically free of allergic conditions and without allergy in the family history). The incidence of blood group antigens A and B was somewhat higher in patients than in controls. These observations are in accordance with the results of previous studies in other populations. In addition, our observations favor the hypothesis that th…
Vitamin E activates CRABP-II gene expression in cultured human fibroblasts, role of protein kinase C
2004
The treatment of human fibroblasts with different tocopherols in the presence of retinol caused an increase in cytoplasmic retinoic acid binding protein II (CRABP-II) mRNA and protein. The possibility of an involvement of protein kinase C (PKC) in the response to tocopherols was supported by the results obtained with the PKC-specific inhibitors, calphostin C and bisindolylmaleimide I. The effect of alpha-tocopherol was prevented by okadaic acid, suggesting that a protein phosphatase is responsible for PKC dephosphorylation produced by the presence of tocopherols. The results shown support the hypothesis that phosphorylation/dephosphorylation of RXRalpha via PKC may be involved in the regula…
The rat liver foci bioassay: II. Investigations on the dose-dependent induction of ATPase-deficient foci by vinyl chloride at very low doses
1985
In order to study the dose-dependence of the genotoxic effect of vinyl chloride (VC) hepatocellular ATPase-deficient foci were evaluated after subchronic exposure of newborn rats. Wistar rats were exposed from day 1 after birth over 10 weeks to 10, 40, 70, 150, 500 and 2000 p.p.m. VC (8 h/day; 5 days/week). One week after cessation of exposure hepatic ATPase-deficient foci were quantitated. For a subsequent investigation lower dose range groups of female and male Wistar and Sprague-Dawley rats were exposed (8 h/day; 5 days/week) to 2.5, 5, 10, 20, 40 and 80 p.p.m. VC. Exposure started at day 3 of life and lasted for 3 weeks. After cessation of exposure the animals were maintained for 10 wee…
The rat liver foci bioassay: I. Age-dependence of induction by vinyl chloride of ATPase-deficient foci
1985
The age-dependence of the induction of pre-neoplastic enzyme-altered hepatic foci was investigated. Rats were exposed (8 h/day, 7 days/week) to 2000 p.p.m. vinyl chloride (VC) either 'transplacentally' (exposure of pregnant females), or immediately after birth for different time intervals (5, 11, 17, 47, 83 days) or from an age of 7 or 21 days onwards. The animals were then kept without further treatment; livers were evaluated for ATPase-deficient foci at the age of 4 months. 'Transplacental' exposure and exposure from day 1 through 5 caused no increase over controls in ATPase-deficient foci, probably due to the lack of hepatocellular proliferation and the low rate of VC metabolism at this …
cAMP-dependent phosphorylation of CYP2B1 as a functional switch for cyclophosphamide activation and its hormonal controlin vitro andin vivo
2001
An important feature of cytochrome P450 (CYP) 2B1 is its high ability to convert the prodrug cyclophosphamide (CPA) to therapeutically cytotoxic metabolites, resulting in interstrand DNA-cross-linking and cell death. We have examined whether and how the phosphorylation of CYP2B1 influences CPA metabolic activation in vitro and in vivo. We found first that only part of the total CYP2B1 pool undergoes phosphorylation. This part is fully inactivated. Second, phosphorylation of CYP2B1 in intact hepatocytes reduced by up to 75% toxification of CPA to mutagenic metabolites (totally dependent on the same preferentially CYP2B-catalyzed 4-hydroxylation of CPA as is the generation of highly cytotoxic…