Gene/Protein Disease Symptom Drug Enzyme Compound
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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)

Proliferating cells and tumour cells maintain a high glycolytic rate even under aerobic conditions. FTO2B cells, a rat hepatoma cell line, show high activities of glycolytic enzymes. Within a culture period of 48 h the cell number increases 5-fold. Replacement of glucose by pyruvate in the culture medium lowers glycolytic enzyme activity and prevents proliferation. Transfection assays revealed that glucose deprivation dramatically decreases the transcriptional activities of the Sp1-dependent aldolase and pyruvate kinase promoters leading to reduced reporter gene expression. Sp1 binding activity is also inhibited by ocadaic acid, an inhibitor of protein phosphatase 1. Western blot analyses with nuclear extracts from FTO2B cells cultured in the presence or absence of glucose revealed differences in the phosphorylation state of Sp1. From these results we conclude that glucose increases the amount of the dephosphorylated form of Sp1 which has a higher DNA binding activity. As a consequence gene expression of the glycolytic enzymes is increased which is a prerequisite for cell proliferation.
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PMID:Glucose regulates the promoter activity of aldolase A and pyruvate kinase M2 via dephosphorylation of Sp1. 940 43

Carbohydrate-responsive element binding protein (ChREBP) is a transcription factor that activates lipogenic genes in liver in response to excess carbohydrate in the diet. ChREBP is regulated in a reciprocal manner by glucose and cAMP. cAMP-dependent protein kinase (protein kinase A) phosphorylates two physiologically important sites in ChREBP, Ser-196, which is located near nuclear localization signal sequence (NLS), and Thr-666, within the basic helix-loop-helix (bHLH) site, resulting in inactivation of nuclear translocation of ChREBP and of the DNA-binding activity, respectively. We demonstrate here that crude cytosolic extracts from livers of rats fed a high carbohydrate diet contained protein phosphatase (PPase) activity that dephosphorylated a peptide containing Ser-196, whereas a PPase in the nuclear extract catalyzed dephosphorylation of Ser-568 and Thr-666. All these PPases are activated specifically by xylulose 5-phosphate (Xu5P), but not by other sugar phosphates. Furthermore, addition of Xu5P elevated PPase activity to the level observed in extracts of fed liver cells. These partially purified PPases were characterized as PP2A-AB delta C by immunoblotting with specific antibodies. These results suggest that (ia) Xu5P-dependent PPase is responsible for activation of transcription of the L-type pyruvate kinase gene and lipogenic enzyme genes, and (ii) Xu5P is the glucose signaling compound. Thus, we propose that the same Xu5P-activated PPase controls both acute and long-term regulation of glucose metabolism and fat synthesis.
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PMID:Xylulose 5-phosphate mediates glucose-induced lipogenesis by xylulose 5-phosphate-activated protein phosphatase in rat liver. 1272 58

1. The present study was designed to examine the role of calcineurin in muscle metabolic components by the administration of the specific calcineurin inhibitor cyclosporine A (CsA) to rats. 2. Male Wistar rats were divided into either a CsA-treated group (CT) or a vehicle-treated group (VT). Cyclosporine A was administered subcutaneously to rats at a rate of 25 mg/kg bodyweight per day for 10 successive days. Thereafter, changes in muscle enzyme activities and glucose transporter (GLUT)-4 and monocarboxylate transporter (MCT)-1 and MCT-4 proteins in the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles were examined. 3. There was a significant increase in MCT-1 and MCT-4 proteins in the soleus muscle in the CT group, but not in the EDL muscle. The activities of hexokinase, pyruvate kinase and lactate dehydrogenase in the soleus muscle also increased significantly in the CT group, but a similar increase in enzyme activity was not seen in EDL muscle. The activities of citrate synthase or malate dehydrogenase and the GLUT-4 protein content were not altered by CsA treatment in either the soleus or EDL muscles. 4. These results seem to imply that calcineurin negatively regulates the components of glucose/lactate metabolism, except for GLUT-4, especially in slow-twitch muscle.
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PMID:Inhibition of calcineurin increases monocarboxylate transporters 1 and 4 protein and glycolytic enzyme activities in rat soleus muscle. 1574 6

Depletion of mitochondrial DNA (mtDNA) or treatment with mitochondrial poison CCCP initiates mitochondrial stress signaling, which operates through altered Ca2+ homeostasis. In C2C12 rhabdomyoblasts and A549 human lung carcinoma cells mitochondrial stress signaling activates calcineurin and a number of Ca2+ responsive factors including ATF, NFAT, CEBP/delta and CREB. Additionally, PKC and MAP kinase are also activated. A number of nuclear gene targets including those involved in Ca2+ storage/release (RyR1, calreticulin, calsequestrin), glucose metabolism (hexokinase, pyruvate kinase, Glut4), oncogenesis (TGFbeta1, cathepsin L, IGFR1, melanoma antigen) and apoptosis (Bcl-2, Bid, Bad, p53) are upregulated. Mitochondrial stress in both C2C12 myoblasts and A549 cells induced morphological changes and invasive phenotypes. These cells also showed markedly increased resistance to etoposide-induced apoptosis that is a hallmark of highly invasive tumors. Our results describe a new mechanism of altered nuclear gene expression and phenotypic changes triggered by mitochondrial dysfunction and mtDNA damage.
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PMID:Mitochondria-to-nucleus stress signaling in mammalian cells: nature of nuclear gene targets, transcription regulation, and induced resistance to apoptosis. 1597 49

Chronic hemodynamic overload on the heart results in pathological myocardial hypertrophy, eventually followed by heart failure. Phosphatase calcineurin is a crucial mediator of this response. Little is known, however, about the role of calcineurin in response to acute alterations in loading conditions of the heart, where it could be mediating beneficial adaptational processes. We therefore analyzed proteome changes following a short-term increase in preload in rabbit myocardium in the absence or presence of the calcineurin inhibitor cyclosporine A. Rabbit right ventricular isolated papillary muscles were cultivated in a muscle chamber system under physiological conditions and remained either completely unloaded or were stretched to a preload of 3 mN/mm(2), while performing isotonic contractions (zero afterload). After 6 h, proteome changes were detected by two-dimensional gel electrophoresis and ESI-MS/MS. We identified 28 proteins that were upregulated by preload compared to the unloaded group (at least 1.75-fold regulation, all P < 0.05). Specifically, mechanical load upregulated a variety of enzymes involved in energy metabolism (i.e., aconitase, pyruvate kinase, fructose bisphosphate aldolase, ATP synthase alpha chain, acetyl-CoA acetyltransferase, NADH ubiquinone oxidoreductase, ubiquinol cytochrome c reductase, hydroxyacyl-CoA dehydrogenase). Cyclosporine A treatment (1 micromol/l) abolished the preload-induced upregulation of these proteins. We demonstrate for the first time that an acute increase in the myocardial preload causes upregulation of metabolic enzymes, thereby increasing the capacity of the myocardium to generate ATP production. This short-term adaptation to enhanced mechanical load appears to critically depend on calcineurin phosphatase activity.
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PMID:Myocardial adaptation of energy metabolism to elevated preload depends on calcineurin activity : a proteomic approach. 1827 99

This study analyzed the differences in karyotype and genetic variation between a mutant and wild-type Siraitia grosvenorii. Genetic variation included changes in genome and gene expression by SRAP molecular markers. Results showed that wild-type S. grosvenorii was diploid, with a chromosome number of 2n = 2x = 28, whereas the mutant was tetraploid with a chromosome number of 2n = 4x = 56. 4573 DNA bands were obtained using 189 different primer combinations, 577 of which were polymorphic, averaging 3.1 bands for each primer pair, while 1998 pairs were identical. There were no apparent differences on bands amplified by most primer pairs. After comparing the diploid and tetraploid strains, the data generally indicated that the polymorphism would be quite low. 2917 cDNA bands were generated using 133 primer combinations, and stable and clearly differential fragments were sorted out, cloned and sequenced. Ninety-two differentially expressed fragments were successfully sequenced. Sequence analysis showed that most fragments had significant homologous nucleotide sequences with resistant to stress and photosynthesis genes, including ribulose-1,5-bisphosphate carboxylase/oxygenase, phosphoenolpyruvate carboxykinase, pyruvate kinase, peroxisomal membrane transporter, NBS-LRR type resistance protein, protein phosphatase and others. The results revealed that the tetraploid strain has more resistant and photosynthesis ability than its diploid relatives, which providing reference information and resources for molecular breeding and seedless Luohanguo.
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PMID:Karyotype analysis and genetic variation of a mutant in Siraitia grosvenorii. 2160 54

Dual specificity protein kinases (DSPKs) are unique enzymes that can execute multiple functions in the cell, which are otherwise performed exclusively by serine/threonine and tyrosine protein kinases. In this study, we have characterized the protein kinases Bas2152 (PrkD) and Bas2037 (PrkG) from Bacillus anthracis. Transcriptional analyses of these kinases showed that they are expressed in all phases of growth. In a serendipitous discovery, both kinases were found to be DSPKs. PrkD was found to be similar to the eukaryotic dual specificity Tyr phosphorylation-regulated kinase class of dual specificity kinases, which autophosphorylates on Ser, Thr, and Tyr residues and phosphorylates Ser and Thr residues on substrates. PrkG was found to be a bona fide dual specificity protein kinase that mediates autophosphorylation and substrate phosphorylation on Ser, Thr, and Tyr residues. The sites of phosphorylation in both of the kinases were identified through mass spectrometry. Phosphorylation on Tyr residues regulates the kinase activity of PrkD and PrkG. PrpC, the only known Ser/Thr protein phosphatase, was also found to possess dual specificity. Genistein, a known Tyr kinase inhibitor, was found to inhibit the activities of PrkD and PrkG and affect the growth of B. anthracis cells, indicating a possible role of these kinases in cell growth and development. In addition, the glycolytic enzyme pyruvate kinase was found to be phosphorylated by PrkD on Ser and Thr residues but not by PrkG. Thus, this study provides the first evidence of DSPKs in B. anthracis that belong to different classes and have different modes of regulation.
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PMID:Unveiling the novel dual specificity protein kinases in Bacillus anthracis: identification of the first prokaryotic dual specificity tyrosine phosphorylation-regulated kinase (DYRK)-like kinase. 2271 36

Using proteomics in tandem with bioinformatics, the secretomes of nonaggressive and aggressive thyroid carcinoma (TC) cell lines were analyzed to detect potential biomarkers for tumor aggressiveness. A panel of nine proteins, activated leukocyte cell adhesion molecule (ALCAM/CD166), tyrosine-protein kinase receptor (AXL), amyloid beta A4 protein, amyloid-like protein 2, heterogeneous nuclear ribonucleoprotein K, phosphoglycerate kinase 1, pyruvate kinase isozyme M2, phosphatase 2A inhibitor (SET), and protein kinase C inhibitor protein 1 (14-3-3 zeta) was chosen to confirm their expression in TC patients' sera and tissues. Increased presurgical circulating levels of ALCAM were associated with aggressive tumors (p = 0.04) and presence of lymph node metastasis (p = 0.018). Increased serum AXL levels were associated with extrathyroidal extension (p = 0.027). Furthermore, differential expression of amyloid beta A4 protein, AXL, heterogeneous nuclear ribonucleoprotein K, phosphoglycerate kinase 1, pyruvate kinase muscle isozyme M2, and SET was observed in TC tissues compared to benign nodules. Decreased nuclear expression of AXL can detect malignancy with 90% specificity and 100% sensitivity (AUC = 0.995, p < 0.001). In conclusion, some of these proteins show potential for future development as serum and/or tissue-based biomarkers for TC and warrant further investigation in a large cohort of patients.
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PMID:Secretome proteins as candidate biomarkers for aggressive thyroid carcinomas. 2331 40


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