Activités phosphatases et carence phosphatée chez des champignons supérieurs

1983 ◽  
Vol 61 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Mireille Calleja ◽  
Jean D'Auzac
Keyword(s):  
Liquid Medium ◽  
Phosphatase Activity ◽  
Inorganic Phosphate ◽  
Culture Medium ◽  
Phosphate Deficiency ◽  
Saprophytic Fungi ◽  
Phosphatase Activities ◽  
The Absolute ◽  
Total Phosphatase Activity

Six mycorrhizal and three saprophytic fungi were collected. They were cultivated in a liquid medium with or without a deficiency in phosphate. Different phosphatase activities were measured from the mycelia: phosphatase activities accessible to an external substrate, phosphatase activities in the culture medium, phosphatase activities of the whole homogenate and two parts of this homogenate (parietal and soluble). With both the mycorrhizal and saprophytic fungi, the deficiency in inorganic phosphate induced a large increase in phosphatase activities which were multiplied on the average by a factor of 72, 56, 43, 64, and 26, for the excreted, accessible, total, parietal, and soluble activities, respectively. If the relative proportions of the various activities were considered, the parietal activity, compared with the total phosphatase activity, increased in six out of nine cases under the effect of phosphate deficiency. The superiority of the parietal activity over the soluble activity was either induced by phosphate deficiency or preexisting. The accessible activity represented only a fraction of the parietal activity and this was usually smaller in a phosphate-deprived medium. Various criteria have been considered to class these fungi in terms of their response to phosphate deficiency, such as the intensity of their phosphatase response to the deficiency and the absolute values in a phosphate-deprived medium of various phosphatase activities. These various criteria do not lead to a classification entirely parallel of the different fungi and they do not discriminate between mycorrhizal and saprophytic fungi.

Inorganic phosphate accumulation and phosphatase activity in the nucleus of maize embryo root cells

1981 ◽  
Vol 47 (1) ◽  
pp. 77-89
Author(s):  
R. Deltour ◽  
S. Fransolet ◽  
R. Loppes
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Inorganic Phosphate ◽  
Specific Activity ◽  
Ultrastructural Localization ◽  
High Concentration ◽  
Root Cells ◽  
Phosphatase Activities ◽  
Root Tissues

The nucleus of growing root cells Zea mays contains a high concentration of inorganic phosphate. In order to verify whether this high nuclear Pi concentration is correlated with the metabolic activity of the nucleus, the Pi has been visualized in root cells of maize embryos at the electron-microscope level during 2 different periods which are both characterized by a spectacular reactivation of the nuclear metabolism, i.e. the early germination and the period of recovery following a thermal treatment given to the seeds after 48 h of germination. In both situations the Pi concentration increased in the nucleus during its reactivation. To verify whether the high nuclear Pi concentration could be of endogenous origin, the phosphatase activities were measured in crude extracts of root tissues during nuclear reactivation. The specific activity was optimal at pH 4.5 and was shown to increase with cellular reactivation. The ultrastructural localization of acid phosphatase activity showed that Pi may be produced at 3 distinct sites: plasmalemma, vacuoles and most probably nucleus itself. High acid phosphatase activities were found in nuclei displaying a high metabolism. Taking these results and previous data into account, we suggest that a correlation may exist between the rate of nuclear transcription, the level of nuclear acid phosphatase activity and the nuclear Pi accumulation.

scholarly journals Histone II-A stimulates glucose-6-phosphatase and reveals mannose-6-phosphatase activities without permeabilization of liver microsomes

1995 ◽  
Vol 310 (1) ◽  
pp. 221-224 ◽  
Author(s):  
J F St-Denis ◽  
B Annabi ◽  
H Khoury ◽  
G van de Werve
Keyword(s):  
Substrate Specificity ◽  
Membrane Permeability ◽  
Phosphatase Activity ◽  
Liver Microsomes ◽  
Microsomal Membrane ◽  
Phosphatase Activities ◽  
Phosphate Hydrolysis ◽  
Mannose 6 Phosphate ◽  
Stimulation Of

The effect of histone II-A on glucose-6-phosphatase and mannose-6-phosphatase activities was investigated in relation to microsomal membrane permeability. It was found that glucose-6-phosphatase activity in histone II-A-pretreated liver microsomes was stimulated to the same extent as in detergent-permeabilized microsomes, and that the substrate specificity of the enzyme for glucose 6-phosphate was lost in histone II-A-pretreated microsomes, as [U-14C]glucose-6-phosphate hydrolysis was inhibited by mannose 6-phosphate and [U-14C]mannose 6-phosphate hydrolysis was increased. The accumulation of [U-14C]glucose from [U-14C]glucose 6-phosphate into untreated microsomes was completely abolished in detergent-treated vesicles, but was increased in histone II-A-treated microsomes, accounting for the increased glucose-6-phosphatase activity, and demonstrating that the microsomal membrane was still intact. The stimulation of glucose-6-phosphatase and mannose-6-phosphatase activities by histone II-A was found to be reversed by EGTA. It is concluded that the effects of histone II-A on glucose-6-phosphatase and mannose-6-phosphatase are not caused by the permeabilization of the microsomal membrane. The measurement of mannose-6-phosphatase latency to evaluate the intactness of the vesicles is therefore inappropriate.

Production and control of extracellular enzymes in Micrococcus sodonensis

1974 ◽  
Vol 20 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Cecily Mills ◽  
J. N. Campbell
Keyword(s):  
Alkaline Phosphatase ◽  
Inorganic Phosphate ◽  
Culture Medium ◽  
Extracellular Enzymes ◽  
Synthetic Medium ◽  
Culture Conditions ◽  
The Other ◽  
Organic Nutrients ◽  
And Control ◽  
Logarithmic Growth

Micrococcus sodonensis has been shown to produce several extracellular enzymes: an alkaline phosphatase, at least two forms of phosphodiesterase, a 5′-nucleotidase, and an alkaline proteinase. The quantitative release of these enzymes into the culture medium during logarithmic growth under all the various culture conditions tested indicates that these enzymes are truly extracellular in nature. Inorganic phosphate repressed the production of the alkaline phosphatase in synthetic as well as in complex media, whereas, the repression of the production of active diesterase and 5′-nucleotidase by inorganic phosphate was partly reversed by the addition of supplemental organic nutrients to the culture medium. Proteinase production was independent of the culture conditions used. A mutant strain of M. sodonensis with an altered production of diesterase was obtained; the other extracellular enzymes were unaffected. These results suggest that the extracellular enzymes of M. sodonensis are not produced in a pleiotropic fashion since the level of one of the enzymes can be changed without affecting a corresponding change in the levels of the other enzymes. An extracellular high molecular weight carbohydrate fraction was shown to be produced by M. sodonensis in synthetic medium. The fraction was also shown to contain glycoprotein.

scholarly journals Flax Inorganic Phosphate Deficiency Responsive miRNAs

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Nataliya V. Melnikova ◽  
Maxim S. Belenikin ◽  
Nadezhda L. Bolsheva ◽  
Alexey A. Dmitriev ◽  
Anna S. Speranskaya ◽  
...  
Keyword(s):  
Inorganic Phosphate ◽  
Phosphate Deficiency

scholarly journals Temporary immersion biorreators: efficient technique for the propagation of the ‘Pircinque’ strawberry

2019 ◽  
Vol 41 (1) ◽  
Author(s):  
Samila Silva Camargo ◽  
Leo Rufato ◽  
Maicon Magro ◽  
André Luiz Kulkamp de Souza
Keyword(s):  
Liquid Medium ◽  
Culture Medium ◽  
Culture Media ◽  
Time Factors ◽  
Efficient Technique ◽  
Control Treatment ◽  
Solid Culture ◽  
Temporary Immersion ◽  
Solid Culture Medium

Abstract The in vitro propagation technique via temporary immersion bioreactors is a tool that, through the culture in a liquid medium, allows an increase in the efficiency of seedling production. Several researches with the strawberry crop have shown greater efficiency of the system compared to the conventional process of micropropagation in solid medium. In this sense, the objective herein was to establish a protocol of multiplication and rooting of the ‘Pircinque’ strawberry, in temporary immersion bioreactors. Two distinct and independent studies were carried out, characterized by the multiplication and rooting stages of strawberry explants, newly introduced and registered in Brazil. Two culture media (MS and KNOP) were studied and, as a control treatment, the growth of the explants in solid culture medium was evaluated with the addition of 5 g L-1 of agar. Different immersion times of the culture medium were explored: five or eight times a day, for 15 minutes. The study was composed of the culture medium and immersion time factors, as well as the control (solid) treatment. It was verified that the use of temporary immersion bioreactors system is an efficient technique for the multiplication and rooting of explants of strawberry cv. Pircinque, when compared to the conventional method of micropropagation with the use of solid culture medium, making it possible to optimize the production of seedlings in biofactories. The MS liquid medium, in contact with explants of ‘Pircinque’ strawberry five times a day, increased the growth of the aerial part and the root system.

Kinetic Method for Determining Acid Phosphatase Activity in Serum with Use of the "CentrifiChem"

1972 ◽  
Vol 18 (8) ◽  
pp. 841-844 ◽  
Author(s):  
Diane L Fabiny-Byrd ◽  
Gerhard Ertingshausen
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Kinetic Method ◽  
Reaction Rates ◽  
Phosphatase Activities ◽  
Fast Red ◽  
Presence And Absence

Abstract Acid phosphatase activity is determined by splitting 1-naphthyl phosphate, concurrently diazotizing the released 1-naphthol with Fast Red TR, and measuring the resulting color. The test is performed in the presence and absence of tartrate. Reaction rates can be continuously monitored, and their difference is proportional to acid phosphatase activity that is inhibited by tartrate. Results for sera with normal and increased acid phosphatase activities are presented and three different methods for acid phosphatase are compared. The kinetic blank used in the reaction eliminates all nonenzymatic contributions to substrate splitting.

scholarly journals Inorganic Phosphate as an Important Regulator of Phosphatases

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Claudia Fernanda Dick ◽  
André Luiz Araújo Dos-Santos ◽  
José Roberto Meyer-Fernandes
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatase ◽  
Metabolic Pathways ◽  
Inorganic Phosphate ◽  
Phosphate Esters ◽  
Regulation System ◽  
Pi Starvation ◽  
Important Regulator ◽  
Phosphatase System ◽  
The Difference

Cellular metabolism depends on the appropriate concentration of intracellular inorganic phosphate (Pi). Pi starvation-responsive genes appear to be involved in multiple metabolic pathways, implying a complex Pi regulation system in microorganisms and plants. A group of enzymes is required for absorption and maintenance of adequate phosphate levels, which is released from phosphate esters and anhydrides. The phosphatase system is particularly suited for the study of regulatory mechanisms because phosphatase activity is easily measured using specific methods and the difference between the repressed and derepressed levels of phosphatase activity is easily detected. This paper analyzes the protein phosphatase system induced during phosphate starvation in different organisms.

scholarly journals Comparison of the substrate specificities of protein phosphatases involved in the regulation of glycogen metabolism in rabbit skeletal muscle

1977 ◽  
Vol 162 (2) ◽  
pp. 423-433 ◽  
Author(s):  
J F Antoniw ◽  
H G Nimmo ◽  
S J Yeaman ◽  
P Cowen
Keyword(s):  
Phosphatase Activity ◽  
Protein Phosphatase ◽  
Glycogen Synthase ◽  
Protein Phosphatases ◽  
Gel Filtration ◽  
Beta Subunit ◽  
Alpha Subunit ◽  
Phosphorylase Kinase ◽  
Substrate Specificities ◽  
Phosphatase Activities

Muscle extracts were subjected to fractionation with ethanol, chromatography on DEAE-cellulose, precipitation with (NH4)2SO4 and gel filtration on Sephadex G-200. These fractions were assayed for protein phosphatase activities by using the following seven phosphoprotein substrates: phosphorylase a, glycogen synthase b1, glycogen synthase b2, phosphorylase kinase (phosphorylated in either the alpha-subunit or the beta-subunit), histone H1 and histone H2B. Three protein phosphatases with distinctive specificities were resolved by the final gel-filtration step and were termed I, II and III. Protein phosphatase-I, apparent mol.wt. 300000, was an active histone phosphatase, but it accounted for only 10-15% of the glycogen synthase phosphatase-1 and glycogen synthase phosphatase-2 activities and 2-3% of the phosphorylase kinase phosphatase and phosphorylase phosphatase activity recovered from the Sephadex G-200 column. Protein phosphatase-II, apparent mol.wt. 170000, possessed histone phosphatase activity similar to that of protein phosphatase-I. It possessed more than 95% of the activity towards the alpha-subunit of phosphorylase kinase that was recovered from Sephadex G-200. It accounted for 10-15% of the glycogen synthase phosphatase-1 and glycogen synthase phosphatase-2 activity, but less than 5% of the activity against the beta-subunit of phosphorylase kinase and 1-2% of the phosphorylase phosphatase activity recovered from Sephadex G-200. Protein phosphatase-III was the most active histone phosphatase. It possessed 95% of the phosphorylase phosphatase and beta-phosphorylase kinase phosphatase activities, and 75% of the glycogen synthase phosphatase-1 and glycogen synthase phosphatase-2 activities recovered from Sephadex G-200. It accounted for less than 5% of the alpha-phosphorylase kinase phosphatase activity. Protein phosphatase-III was sometimes eluted from Sephadex-G-200 as a species of apparent mol.wt. 75000(termed IIIA), sometimes as a species of mol.wt. 46000(termed IIIB) and sometimes as a mixture of both components. The substrate specificities of protein phosphatases-IIA and -IIB were identical. These findings, taken with the observation that phosphorylase phosphatase, beta-phosphorylase kinase phosphatase, glycogen synthase phosphatase-1 and glycogen synthase phosphatase-2 activities co-purified up to the Sephadex G-200 step, suggest that a single protein phosphatase (protein phosphatase-III) catalyses each of the dephosphorylation reactions that inhibit glycogenolysis or stimulate glycogen synthesis. This contention is further supported by results presented in the following paper [Cohen, P., Nimmo, G.A. & Antoniw, J.F. (1977) Biochem. J. 1628 435-444] which describes a heat-stable protein that is a specific inhibitor of protein phosphatase-III.

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