Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
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Gene/Protein
Disease
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Drug
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Target Concepts:
Gene/Protein
Disease
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Query: EC:3.1.3.16 (
calcineurin
)
17,112
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
In bovine iris sphincter, myo-inositol 1,4,5-trisphosphate (IP3) 5-phosphatase and
myo-inositol 1-phosphate
(IP1) monophosphatase are mainly localized in the microsomal and soluble fractions, respectively. Studies on the properties of these enzymes can be summarized as follows. (1) The microsomal IP3 5-phosphatase hydrolyzed IP3 to myo-inositol 1,4-bisphosphate with an apparent Km of 28 microM and Vmax of 32 nmol/min per mg protein. The IP1 monophosphatase in the soluble fraction hydrolyzed IP1 into free inositol with an apparent Km of 89 microM and Vmax of 7 nmol/min per mg protein. (2) IP3 5-phosphatase and IP1 monophosphatase had optimal pH values at 8.0 and 7.0, respectively. (3) Both enzymes required Mg2+ and their highest specific activities were at a cation concentration of 2 mM. (4) Ca2+ (> 0.5 microM) exerted an inhibitory effect on IP3 5-phosphatase activity, and marked inhibition (47%) was observed at a concentration of 10 microM. Higher concentrations of the cation (> 100 microM) were required to inhibit IP1 monophosphatase. (5) IP1 monophosphatase, but not IP3 5-phosphatase, was inhibited by Li+. Li+ had no effect on the contractile response in this smooth muscle. (6) Both enzymes were inhibited by ATP and by the thiol-blocking agent, disulfiram. In addition, thimerosal, a thiol reagent, also inhibited the IP3 5-phosphatase activity. (7) Protein phosphorylation of the microsomal and soluble fractions with PKA or PKC had no effect on the activities of these enzymes. (8) Okadaic acid, a
protein phosphatase
inhibitor, had no effect on the activity of IP3 5-phosphatase. However, in the intact iris sphincter the toxin significantly reduced the carbachol-induced IP3 production, 1,2-diacylglycerol formation, measured as phosphatidic acid, and caused muscle relaxation.
...
PMID:Studies on the properties of myo-inositol-1,4,5-trisphosphate 5-phosphatase and myo-inositol monophosphatase in bovine iris sphincter smooth muscle: effects of okadaic acid and protein phosphorylation. 818 62
The common ice plant, Mesembryanthemum crystallinum L., is a eu-halophytic model species with an environmental stress-initiated switch from C
3
photosynthesis to crassulacean acid metabolism (CAM). Phosphoenolpyruvate carboxylase activity in 6-week-old plants exposed to salt stress for 5 days was ~15-fold higher than before stress, indicating the salinity-dependent induction of the C
3
to CAM transition. Five plant
protein phosphatase
type 2C (PP2C) genes were cloned, representative of five of the 10 plant PP2C sub-families. We measured mRNA levels of these PP2Cs and of
myo-inositol 1-phosphate
synthase (Inps1) in 6-week-old plants before (C
3
) and after (CAM) salt stress. Remarkably, four PP2C genes and Inps1 were expressed with a diurnal fluctuation in plants in C
3
mode. After salt-induced CAM induction, the six genes were expressed with more prominent fluctuations than before stress, suggesting that these PP2C genes may be involved in the diurnal regulation of protein phosphorylation in CAM. Under continuous light treatment the expression of two PP2C genes continued to fluctuate, indicating that their expression is controlled by circadian rhythm.
...
PMID:Diurnal expression of five protein phosphatase type 2C genes in the common ice plant, Mesembryanthemum crystallinum. 3268 86
