Binding of vanadium (IV) to the phosphatase calcineurin

Parra-Diaz, Dennisse; Wang, Qun; Lee, Ernest Y.C.; Echegoyen, Luís; Puett, David

doi:10.1016/0014-5793(95)01245-2

Cited by 7 publications

(3 citation statements)

References 18 publications

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“…Vanadate ions from NaVO 4 and Na 3 VO 4 have been shown to mediate phosphorylation of tumor suppressor p53 protein (Suzuki, et al 2007). Vanadate compounds were also reported to inhibit protein phosphatases other than tyrosine specific ones (Parra-Diaz, et al 1995, Reiter, et al 2002. Tyrosine de/phosphorylation is a rare event in yeast: there are no true protein tyrosine kinases and just a few phosphatases (Chi, et al 2007).…”

Section: Discussionmentioning

confidence: 99%

The yeast Mig1 transcriptional repressor is dephosphorylated by glucose-dependent and independent mechanisms

Shashkova

Wollman

Leake

et al. 2017

Preprint

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Saccharomyces cerevisiae AMPK/Snf1 regulates glucose derepression of genes required for utilization of alternative carbon sources through the transcriptional repressor Mig1. It has been suggested that the Glc7-Reg1 phosphatase dephosphorylates Mig1. Here we report that Mig1 is dephosphorylated by Glc7-Reg1 in an apparently glucose-dependent mechanism but also by a mechanism independent of glucose and Glc7-Reg1. In addition to serine/threonine phosphatases another process including tyrosine phosphorylation seems crucial for Mig1 regulation. Taken together, Mig1 dephosphorylation appears to be controlled in a complex manner, in line with the importance for rapid and sensitive regulation upon altered glucose concentrations in the growth medium.

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Section: Discussionmentioning

confidence: 99%

The yeast Mig1 transcriptional repressor is dephosphorylated by glucose-dependent and independent mechanisms

Shashkova

Wollman

Leake

et al. 2017

Preprint

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“…In rat tissues treated with vanadium complexes, about 90% of vanadium was in vanadyl form (VO 2+ ) [23] . Vanadyl ions bind to many proteins such as ferritins, albumin, transferrin, phosphatase calcineurin [24][25][26][27] , and F 1 -ATPase [28,29] . The affinity for these targets is at about 10 −10 mol/L [30] .…”

Section: Chemical Biologymentioning

confidence: 99%

Vanadyl ions binding to GroEL (HSP60) and inducing its depolymerization

et al. 2007

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Several vanadium compounds have been known for the hypoglycemic and anticancer effects. However, the mechanisms of the pharmacological and toxicological effects were not clear. In this work, we investigated the potential targets of vanadium in mitochondria. Vanadyl ions were found to bind to mitochondria from rat liver with a stoichiometry of 244±58 nmol/mg protein and an apparent dissociation constant (K d ) of (2.0±0.8)×10 −16 mol/L. Using size exclusion chromatography, a vanadium-binding protein was isolated and identified to be the 60-kDa heat shock protein (HSP60) by mass spectrometry analysis and immunoassays. Additionally, binding of vanadyl ions was found to result in depolymerization of homo-oligomeric HSP60 (GroEL). HSP60 is an indispensable molecular chaperone and involved in many kinds of pathogenesis of inflammatory and autoimmune diseases, e.g. type 1 diabetes. Our results suggested that HSP60 could be a novel important target involved in the biological and/or toxicological effects of vanadium compounds.vanadium, mitochondria, HSP60, diabetes Vanadium compounds have recently attracted growing attention to hypoglycemic effects in clinical trials and diabetic animal models [1, 2] as well as the potential in cancer prevention and therapeutical treatment [3] . The underlying mechanisms of vanadium compounds have been proposed to be insulin receptor activation [4] and inhibition of protein tyrosine kinase (PTPase) [5] . However, there was also evidence suggesting that the actions of vanadium were not relevant to the insulin-induced signal transduction [6] . In addition, there have been great concerns on the toxicity of vanadium compounds for therapeutic applications.Currently, alteration of mitochondrial functions was proposed to closely relate to insulin resistance [7 -12] ; while the capacity of mitochondrial bioenergetics was suggested to be the best predictor for the development of type 2 diabetes [9,10] . The bioenergetic capacity of skeletal muscle mitochondria was shown to be impaired in insulin-resistant offspring of parents with type 2 diabetes [12] . Diabetic islets from type 2 diabetic patients exhibited lower insulin secretion in response to glucose, associating with lower ATP levels, lower ATP/ADP ratio, and impaired hyperpolarization of the mitochondrial membrane potential [7] . On the other hand, mitochondria are also key intersections in many cellular signal transductions including apoptosis and oxidative stress [13] .Previously, we found that vanadate and organic vanadium complexes could increase mitochondrial membrane potential and induce intracellular reactive oxygen species [14] , suggesting that vanadium compounds could affect mitochondrial functions. Elucidating the interactions of vanadium species with mitochondria would be

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“…In vivo, vanadium occurs mainly in its V oxidation state, vanadate, but this is rapidly reduced to the IV oxidation state, vanadyl (9). Using electron spin resonance (ESR) spectroscopy, we recently showed that vanadyl binds to CN and the B-subunit and, interestingly, can increase CN activity (10).…”

Section: Introductionmentioning

confidence: 99%

Conformation Changes in Brain Calcineurin in Diabetic Rats with or without Treatment with Vanadyl Sulfate

Wang

2001

IUBMB Life

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Recent studies have shown that vanadium salts are able to reduce blood glucose in diabetics and overcome, to some degree, insulin resistance. This paradigm has been followed to monitor the effects of diabetes and vanadyl treatment on brain calcineurin (CN), an important protein phosphatase. Male rats were rendered diabetic by a single injection of streptozotocin (STZ), resulting in an elevation of blood glucose from 108 +/- 13 to >400 mg/dl. Diabetic animals were given vanadyl sulfate trihydrate (0.5 mg/dl.) in their drinking water for 3 weeks, which led to a fall in blood glucose to 156 +/- 53 mg/ml. Brain CN activity (units/mg brain protein) in diabetic rats was 77% that of control animals, whereas vanadyl-treated diabetic animals were characterized by CN activities like that of controls. CN was purified from brains of control animals, STZ-induced diabetic animals, and STZ-induced diabetic animals receiving vanadyl, then spin-labeled with 3-maleimide-proxyl and studied via electron spin resonance spectroscopy. The rotational correlation time of CN from control animals and vanadyl-treated diabetic animals was 6.4 x 10(-11) s(-1), whereas that from STZ-induced-diabetic animals was 8 x 10(-11) s(-1). Thus, STZ-induced diabetes in rats results in an increase in the rotational correlation time of brain CN relative to control animals, yet vanadyl treatment of STZ-induced diabetic animals reduced the rotational correlation time to that of control. These data suggest that diabetes can lead to apparent conformational changes in brain CN; also, CN conformation in diabetic rats was restored by vanadyl treatment.

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Binding of vanadium (IV) to the phosphatase calcineurin

Cited by 7 publications

References 18 publications

The yeast Mig1 transcriptional repressor is dephosphorylated by glucose-dependent and independent mechanisms

The yeast Mig1 transcriptional repressor is dephosphorylated by glucose-dependent and independent mechanisms

Vanadyl ions binding to GroEL (HSP60) and inducing its depolymerization

Conformation Changes in Brain Calcineurin in Diabetic Rats with or without Treatment with Vanadyl Sulfate

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