Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Two antipeptide antibodies, one against the peptide corresponding to residues 307-327 (alpha Y91) and one against the peptide corresponding to the C-terminal portion (alpha C92) of the deduced amino acid sequence of the extracellular signal-regulated kinase 1 (ERK1), precipitated two 41-kDa and/or two 43-kDa phospho-proteins from mitogen-stimulated Swiss 3T3 cells. Electrophoretic mobilities on two-dimensional gels of the immunoprecipitated 41- and 43-kDa phosphoproteins were similar to those of the 41- and 43-kDa cytosol proteins, whose increased tyrosine phosphorylation we and others had originally identified in various mitogen-stimulated cells (Cooper, J. A., Sefton, B. M., and Hunter, T. (1984) Mol. Cell. Biol. 4, 30-37; Kohno, M. (1985) J. Biol. Chem. 260, 1771-1779); phosphopeptide map analysis revealed that they were respectively identical molecules. All those phosphoproteins contained phosphotyrosine, and the more acidic forms contained additional phosphothreonine. Immunoprecipitated 41- and 43-kDa phosphoproteins had serine/threonine kinase activity toward myelin basic protein (MBP) and microtuble-associated protein 2 (MAP2). With the combination of two-dimensional gel electrophoresis and the kinase assay in MBP-containing polyacrylamide gels of the alpha Y91 immunoprecipitates, with or without phosphatase 2A treatment, we showed that only their acidic forms were active. These results clearly indicate that 41- and 43-kDa proteins, the increased tyrosine phosphorylation of which is rapidly and commonly induced by mitogen stimulation of fibroblasts, are family members of ERKs/MAP2 kinases and that phosphorylation both on tyrosine and threonine residues is necessary for their activation.
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PMID:Mitogen-induced tyrosine-phosphorylated 41- and 43-kDa proteins are family members of extracellular signal-regulated kinases/microtubule-associated protein 2 kinases. 131 74

Two site-specific antibodies have been prepared by immunizing rabbits with chemically synthesized peptides derived from the partial cDNA-predicted amino acid sequence of extracellular signal-regulated kinase 1 (ERK1), which has been proposed to encode the microtubule-associated protein 2 (MAP2) kinase (Boulton, T. G., Yancopoulos, G. D., Gregory, J. S., Slauer, C., Moomaw, C., Hsu, J., and Cobb, M. H. (1990) Science 249, 64-67). With immunoprecipitation in the presence of sodium dodecyl sulfate (SDS) and Western blotting, an antibody to the peptide containing triple tyrosine residues (alpha Y91) resembling one of the insulin receptor autophosphorylation sites specifically recognized 42- and 44-kDa proteins. On the other hand, an antibody to the peptide corresponding to the COOH terminus portions (alpha C92) of the ERK1 cDNA gene product recognized the 44-kDa protein much more efficiently than the 42-kDa protein. With immunoprecipitation in the absence of SDS, alpha Y91 could barely recognize these two proteins and alpha C92 recognized the 44-kDa protein but failed to recognize the 42-kDa protein. Kinase assays in myelin basic protein (MBP)-containing gel, after SDS-polyacrylamide gel electrophoresis, revealed that insulin or 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated MBP kinase activity in alpha Y91 immunoprecipitates comigrated at molecular mass 42 and 44 kDa. On the other hand, the stimulated MBP kinase activity in alpha C92 immunoprecipitates comigrated only at molecular mass 44 kDa. Insulin stimulated the MBP kinase activity in gels and phosphorylation of these two proteins by greater than 10-fold with a maximal level at 5 min. Insulin and TPA rapidly stimulate the phosphorylation of the 42- and 44-kDa proteins via de novo threonine and tyrosine phosphorylation. Tryptic phosphopeptide mapping analysis of the 42- and 44-kDa proteins, respectively, revealed a single major phosphopeptide containing phosphothreonine and phosphotyrosine, which was common to both insulin- and TPA-stimulated phosphoproteins. Protein phosphatase 2A treatment of these two phosphoproteins caused a complete loss of kinase activity with selective dephosphorylation of phosphothreonine. These data strongly suggest that these two proteins are highly related to the mitogen-activated protein (MAP) kinase with an apparent molecular mass of 42 kDa (Ray, L. B., and Sturgill, T. W. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 3753-3757) and that these two immunologically similar but distinct MBP/MAP2 kinases may represent isozymic forms of MBP/MAP2 kinases. These data also demonstrate that insulin and TPA activate MBP/MAP2 kinase activity by de novo phosphorylation of threonine and tyrosine residues via a very similar pathway.
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PMID:Insulin and 12-O-tetradecanoylphorbol-13-acetate activation of two immunologically distinct myelin basic protein/microtubule-associated protein 2 (MBP/MAP2) kinases via de novo phosphorylation of threonine and tyrosine residues. 166 17

Soluble, monomeric simian virus 40 (SV40) small-t antigen (small-t) was purified from bacteria and assayed for its ability to form complexes with protein phosphatase 2A (PP2A) and to modify its catalytic activity. Different forms of purified PP2A, composed of combinations of regulatory subunits (A and B) with a common catalytic subunit (C), were used. The forms used included free A and C subunits and AC and ABC complexes. Small-t associated with both the free A subunit and the AC form of PP2A, resulting in a shift in mobility during nondenaturing polyacrylamide gel electrophoresis. Small-t did not interact with the free C subunit or the ABC form. These data demonstrate that the primary interaction is between small-t and the A subunit and that the B subunit of PP2A blocks interaction of small-t with the AC form. The effect of small-t on phosphatase activity was determined by using several exogenous substrates, including myosin light chains phosphorylated by myosin light-chain kinase, myelin basic protein phosphorylated by microtubule-associated protein 2 kinase/ERK1, and histone H1 phosphorylated by protein kinase C. With the exception of histone H1, small-t inhibited the dephosphorylation of these substrates by the AC complex. With histone H1, a small stimulation of dephosphorylation by AC was observed. Small-t had no effect on the activities of free C or the ABC complex. A maximum of 50 to 75% inhibition was obtained, with half-maximal inhibition occurring at 10 to 20 nM small-t. The specific activity of the small-t/AC complex was similar to that of the ABC form of PP2A with myosin light chains or histone H1 as the substrate. These results suggested that small-t and the B subunit have similar qualitative and quantitative effects on PP2A enzyme activity. These data show that SV40 small-antigen binds to purified PP2A in vitro, through interaction with the A subunit, and that this interaction inhibits enzyme activity.
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PMID:Control of protein phosphatase 2A by simian virus 40 small-t antigen. 170 74

The dominant insulin-stimulated ribosomal protein S6 kinase activity was purified to near homogeneity from insulin-treated 32P-labeled rat H4 hepatoma cells and found to copurify with a 70-kDa 32P-labeled polypeptide. The dominant S6 kinase purified from livers of cycloheximide-treated rats is also a 70-kDa polypeptide. Antiserum raised against rat liver S6 kinase specifically immunoprecipitates the purified 32P-labeled H4 hepatoma insulin-stimulated S6 kinase. This antiserum also specifically precipitates insulin-stimulated S6 kinase activity directly from cytosolic extracts of H4 cells. Immune complexes prepared from the cytosol of 32P-labeled H4 cells contain several 32P-labeled polypeptides; only a 70-kDA 32P-labeled peptide, however, is specifically displaced by preadsorption of the antiserum with nonradioactive rat liver S6 kinase. Insulin treatment increases the 32P content of the immunoprecipitated 70-kDa S6 kinase polypeptide 3- to 4-fold over basal levels; 32P-labeled serine, some 32P-labeled threonine, but no 32P-labeled tyrosine are detected after partial acid hydrolysis. Tryptic peptide maps indicate that the insulin-stimulated S6 kinase purified from 32P-labeled H4 cells is phosphorylated at multiple sites distinct from those which participate in autophosphorylation in vitro. Autophosphorylation of rat liver S6 kinase in vitro does not modify S6 kinase activity. The S6 kinases purified from liver of cycloheximide-treated rat and H4 hepatoma insulin-stimulated enzyme are each completely deactivated by incubation with protein phosphatase type 2A in both autophosphorylating and 40S S6 phosphorylating activities. The phosphatase 2A-deactivated 70-kDa S6 kinase is neither reactivated nor phosphorylated by partially purified insulin-stimulated microtubule-associated protein 2 kinase, in experiments where Xenopus S6 kinase II undergoes phosphorylation and partial reactivation. Thus insulin activates the 70-kDa S6 kinase by promoting phosphorylation of specific serine/threonine residues on the enzyme polypeptide, probably through activating an as-yet-unidentified serine/threonine protein kinase distinct from microtubule-associated protein 2 kinase.
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PMID:Insulin activates a 70-kDa S6 kinase through serine/threonine-specific phosphorylation of the enzyme polypeptide. 212 50

2,3,7,8-Tetrachloro-p-dioxin (TCDD) induced a modest stimulation of nuclear protein phosphorylation in explant tissue cultures in 10 min, followed by a substantial decrease in the level of total protein phosphorylation activity in the nucleus. Curiously, this TCDD-induced decline in nuclear protein phosphorylation was accompanied by an increase in cytosolic and extranuclear protein phosphorylation activity. One of the main causes for such a decrease in the protein phosphorylation activity in the nucleus appears to be related to some increase in protein phosphatase activities as judged by the counteractions of okadaic acid and Na3VO4 to the above effect. In addition, TCDD induced changes in nuclear protein kinase activities as well. Manganese-stimulated protein kinase was found to be the predominant type of nuclear protein phosphorylating activity affected by TCDD, with 60% of the total activity due to heparin-sensitive casein kinase II (CK II), a major nuclear protein kinase. The level of CK II activity in the nuclear protein preparation from adipose tissue of TCDD-treated guinea pigs (1 microgram/kg) in the presence of 100 nM heparin was only 35% of the control value after 24 hr. In addition, TCDD was found to increase the protein kinase C and microtubule-associated protein 2 kinase activities as early as 15 min after treatment in isolated adipose tissues in culture. Under in situ incubation conditions with explant tissues in culture, TCDD rapidly enhanced the DNA binding activity of the transcriptional factor AP-1, whereas the same treatment reduced c-Myc DNA binding activity. Genistein, a specific protein tyrosine kinase inhibitor, abolished the stimulatory effect of TCDD on AP-1 binding activity, but not on DNA binding activity of c-Myc. Phorbol ester (TPA) increased the binding activity of AP-1 and c-Myc, as expected. However, TCDD in combination with TPA caused a slight reduction in binding activity of both transcriptional factors. On the other hand, in the presence of forskolin, the stimulatory effect of TCDD on AP-1 binding activity and the inhibitory effect on c-Myc were still apparent. Okadaic acid almost abolished the binding activity of c-Myc, whereas in combination with TCDD a stimulatory effect was found. These observations are consistent with the idea that TCDD regulates the DNA binding activity of AP-1 and c-Myc mainly through modulating their states of phosphorylation by altering protein kinase and phosphatase activities.
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PMID:Regulation by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) of the DNA binding activity of transcriptional factors via nuclear protein phosphorylation in guinea pig adipose tissue. 748 34

A small number of signaling cascades represented by mitogen-activated protein kinases, phosphoinositol-3-kinase, protein kinase C, signal transducers and activators of transcription, Ca2+/calcineurin, and a few other molecules are linked to an incomparably large number of surface receptors. Parallel activation of several of these pathways and the existence of isozymes for a number of signal transmitting molecules generate the required complexity and specificity matching the receptor variety. Here we show that the proinflammatory mediator TNF-alpha and the growth factor IL-5 are activated along common and distinct signaling cascades in allergically stimulated murine mast cells. Both of them are dependent on Ca2+ influx, activation of calcineurin and nuclear factor of activated T cells as well as a member of the atypical PKC family, most likely PKCmu. Additionally, mitogen-activated protein kinases for TNF-alpha and members of the classical or nonclassical PKCs for IL-5, respectively, were identified as additional required pathways. Inhibition of the classical and nonclassical PKCs, however, does not abrogate IL-5 induction but instead leads to a switch to mitogen-activated protein kinases, which then become essential. The activated branches of this "salvage" signaling cascade are represented by extracellular signal-regulated kinase 1/2 and c-jun NH2 terminal kinase 1 in allergically stimulated mast cells.
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PMID:Common and distinct signaling pathways mediate the induction of TNF-alpha and IL-5 in IgE plus antigen-stimulated mast cells. 955 81

Degradation of collagenous extracellular matrix by collagenase 1 (also known as matrix metalloproteinase 1 [MMP-1]) plays a role in the pathogenesis of various destructive disorders, such as rheumatoid arthritis, chronic ulcers, and tumor invasion and metastasis. Here, we have investigated the role of distinct mitogen-activated protein kinase (MAPK) pathways in the regulation of MMP-1 gene expression. The activation of the extracellular signal-regulated kinase 1 (ERK1)/ERK2 (designated ERK1,2) pathway by oncogenic Ras, constitutively active Raf-1, or phorbol ester resulted in potent stimulation of MMP-1 promoter activity and mRNA expression. In contrast, activation of stress-activated c-Jun N-terminal kinase and p38 pathways by expression of constitutively active mutants of Rac, transforming growth factor beta-activated kinase 1 (TAK1), MAPK kinase 3 (MKK3), or MKK6 or by treatment with arsenite or anisomycin did not alone markedly enhance MMP-1 promoter activity. Constitutively active MKK6 augmented Raf-1-mediated activation of the MMP-1 promoter, whereas active mutants of TAK1 and MKK3b potently inhibited the stimulatory effect of Raf-1. Activation of p38 MAPK by arsenite also potently abrogated stimulation of MMP-1 gene expression by constitutively active Ras and Raf-1 and by phorbol ester. Specific activation of p38alpha by adenovirus-delivered constitutively active MKK3b resulted in potent inhibition of the activity of ERK1,2 and its upstream activator MEK1,2. Furthermore, arsenite prevented phorbol ester-induced phosphorylation of ERK1,2 kinase-MEK1,2, and this effect was dependent on p38-mediated activation of protein phosphatase 1 (PP1) and PP2A. These results provide evidence that activation of signaling cascade MKK3-MKK3b-->p38alpha blocks the ERK1,2 pathway at the level of MEK1,2 via PP1-PP2A and inhibits the activation of MMP-1 gene expression.
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PMID:p38 mitogen-activated protein kinase-dependent activation of protein phosphatases 1 and 2A inhibits MEK1 and MEK2 activity and collagenase 1 (MMP-1) gene expression. 1125 86

IL-9 is a Th2 cytokine that exerts pleiotropic activities on T cells, B cells, mast cells, hematopoietic progenitors, and lung epithelial cells, but no effect of this cytokine has been reported so far on mononuclear phagocytes. Human blood monocytes preincubated with IL-9 for 24 h before LPS or PMA stimulation exhibited a decreased oxidative burst, even in the presence of IFN-gamma. The inhibitory effect of IL-9 was specifically abolished by anti-hIL-9R mAb, and the presence of IL-9 receptors was demonstrated on human blood monocytes by FACS. IL-9 also down-regulated TNF-alpha and IL-10 release by LPS-stimulated monocytes. In addition, IL-9 strongly up-regulated the production of TGF-beta1 by LPS-stimulated monocytes. The suppressive effect of IL-9 on the respiratory burst and TNF-alpha production in LPS-stimulated monocytes was significantly inhibited by anti-TGF-beta1, but not by anti-IL-10Rbeta mAb. Furthermore, IL-9 inhibited LPS-induced activation of extracellular signal-regulated kinase 1/2 mitogen-activated protein kinases in monocytes through a TGF-beta-mediated induction of protein phosphatase activity. In contrast, IL-4, which exerts a similar inhibitory effect on the oxidative burst and TNF-alpha release by monocytes, acts primarily through a down-regulation of LPS receptors. Thus, IL-9 deactivates LPS-stimulated blood mononuclear phagocytes, and the mechanism of inhibition involves the potentiation of TGF-beta1 production and extracellular signal-regulated kinase inhibition. These findings highlight a new target cell for IL-9 and may account for the beneficial activity of IL-9 in animal models of exaggerated inflammatory response.
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PMID:IL-9 inhibits oxidative burst and TNF-alpha release in lipopolysaccharide-stimulated human monocytes through TGF-beta. 1193 70

We have previously demonstrated that calcineurin and p38 mitogen-activated protein kinase (MAPK) are up-regulated in the hearts of mdx mice. However, the degree of up-regulation observed was variable, which may reflect variable levels of daily physical activities among the mice. To investigate whether or not exercise affects dystrophic features and activates intracellular signaling molecules in mdx hearts, we subjected mdx and C57BL/10 mice to treadmill exercise and examined intracellular signaling molecules in cardiac muscles, at the protein level. The heart to body weight ratio was significantly increased in exercised mdx mice. Histopathology in exercised mdx hearts showed extensive infiltration of inflammatory cells, together with increases in interstitial fibrosis and adipose tissues, all of which were not observed either in exercised C57BL/10 or non-exercised mdx hearts. Phosphorylated p38 MAPK, phosphorylated extracellular signal-regulated kinase 1/2 and calcineurin, but not phosphorylated c-Jun N-terminal kinase 1, were up-regulated in exercised mdx hearts compared to exercised C57BL/10 or non-exercised mdx hearts. These data suggest that physical exercise accelerates the dystrophic process through activation of intracellular signaling molecules in dystrophin-deficient hearts.
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PMID:Progression of dystrophic features and activation of mitogen-activated protein kinases and calcineurin by physical exercise, in hearts of mdx mice. 1204 63

Glioblastoma is a severe type of primary brain tumor and its invasion is strongly correlated with the secretion of matrix metalloproteinases (MMPs). To investigate a role of PTEN, a tumor suppressor gene, in the regulation of hyaluronic acid (HA)-induced invasion of glioma cells, we examined the secretion of MMP-9 in various glioma cells with or without a functional PTEN gene. The secretion of MMP-9 in glioma cells lacking functional PTEN (U87MG, U251MG, and U373MG) was induced by HA, although not in wildtype (wt)-PTEN-harboring cells (LN229, LN18, and LN428). In addition, stable expression of wt-PTEN into U87MG cells significantly decreased the secretion of HA-induced MMP-9 and basal levels of MMP-2, inhibiting the activation of focal adhesion kinase and extracellular signal-regulated kinase 1/2, whereas the secretion levels of the tissue inhibitor of metalloproteinase-1 and -2 were increased, finally resulting in the inhibition of invasion by HA in vitro. Ectopic expressions of adenoviral (Ad)-wt-PTEN and -lipid phosphatase-deficient (G129E)-PTEN, but not both protein and -lipid phosphatase-deficient (C124S)-PTEN, reduced MMP-9 secretion and invasion by HA. These results were also confirmed by expressions of Ad-wt-PTEN and Ad-G129E-PTEN in other glioblastoma cells lacking functional PTEN, U251MG, and U373MG. These findings strongly suggest the possibility that PTEN may block HA-induced MMP-9 secretion and invasion through its protein phosphatase activity.
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PMID:PTEN suppresses hyaluronic acid-induced matrix metalloproteinase-9 expression in U87MG glioblastoma cells through focal adhesion kinase dephosphorylation. 1241 63


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