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PMID |
Sentence |
1 |
1645334
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pp54 microtubule-associated protein-2 (MAP-2) kinase, a recently discovered protein serine/threonine kinase (Kyriakis, J., and Avruch, J. (1990) J.
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2 |
1645334
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Treatment with recombinant rat brain protein tyrosine phosphatase-1 deactivates pp54 MAP-2 kinase, concomitant with the removal of phosphotyrosine residues.
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3 |
1645334
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Protein (serine/threonine) phosphatase-1 also deactivates pp54 MAP-2 kinase in a specific fashion. pp54 MAP-2 kinase joins pp42 MAP-2 kinase and cdc2/maturation-promoting factor as one of only three serine/threonine protein kinases known to be regulated by phosphorylation at both tyrosine and, independently, at serine/threonine residues.
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4 |
7487920
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Two compounds, (naphth-2-yl) difluoromethylphosphonic acid (12) and (napthy-1-yl) difluoromethylphosphonic acid (13) have been found to inhibit dephosphorylation of [32P]insulin receptors by PTP-1B, a protein tyrosine phosphatase (PTPase), with IC50 values of 40-50 microM.
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5 |
7487920
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Compound 12 competitively inhibited insulin-receptor dephosphorylation by PTP-1B.
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6 |
7487920
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Nine out of the 15 compounds potently inhibited serine/threonine phosphatase PP-2A activity without any effect on serine/threonine phosphatase PP-1 when tested at a concentration as high as 675 microM.
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7 |
7487920
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These PP-2A inhibitors could be useful tools for studying serine/threonine-phosphatase-mediated signal transduction.
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8 |
7487920
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Two compounds, 12 and 13, inhibited both tyrosine phosphatase PTP-1B and serine/threonine phosphatase PP-2A with similar potency; IC50 values being 40-50 microM in both cases.
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9 |
7487920
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Two compounds, (naphth-2-yl) difluoromethylphosphonic acid (12) and (napthy-1-yl) difluoromethylphosphonic acid (13) have been found to inhibit dephosphorylation of [32P]insulin receptors by PTP-1B, a protein tyrosine phosphatase (PTPase), with IC50 values of 40-50 microM.
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10 |
7487920
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Compound 12 competitively inhibited insulin-receptor dephosphorylation by PTP-1B.
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11 |
7487920
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Nine out of the 15 compounds potently inhibited serine/threonine phosphatase PP-2A activity without any effect on serine/threonine phosphatase PP-1 when tested at a concentration as high as 675 microM.
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12 |
7487920
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These PP-2A inhibitors could be useful tools for studying serine/threonine-phosphatase-mediated signal transduction.
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13 |
7487920
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Two compounds, 12 and 13, inhibited both tyrosine phosphatase PTP-1B and serine/threonine phosphatase PP-2A with similar potency; IC50 values being 40-50 microM in both cases.
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14 |
7487920
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Two compounds, (naphth-2-yl) difluoromethylphosphonic acid (12) and (napthy-1-yl) difluoromethylphosphonic acid (13) have been found to inhibit dephosphorylation of [32P]insulin receptors by PTP-1B, a protein tyrosine phosphatase (PTPase), with IC50 values of 40-50 microM.
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15 |
7487920
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Compound 12 competitively inhibited insulin-receptor dephosphorylation by PTP-1B.
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16 |
7487920
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Nine out of the 15 compounds potently inhibited serine/threonine phosphatase PP-2A activity without any effect on serine/threonine phosphatase PP-1 when tested at a concentration as high as 675 microM.
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17 |
7487920
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These PP-2A inhibitors could be useful tools for studying serine/threonine-phosphatase-mediated signal transduction.
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18 |
7487920
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Two compounds, 12 and 13, inhibited both tyrosine phosphatase PTP-1B and serine/threonine phosphatase PP-2A with similar potency; IC50 values being 40-50 microM in both cases.
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19 |
7789633
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The purpose of this study was to examine the effect of the serine/threonine phosphatase inhibitor okadaic acid and the tyrosine phosphatase inhibitors phenylarsine oxide and vanadate on 2-deoxyglucose transport in insulin-resistant human skeletal muscle.
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20 |
7822300
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Stimulation of protein phosphatase-1 activity by insulin in rat adipocytes.
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21 |
7822300
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In this study, we examined the distribution of protein serine/threonine phosphatase-1 (PP-1) and analyzed the effect of insulin on PP-1 and its mechanism of activation in freshly isolated rat adipocytes.
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22 |
7822300
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The adipocyte particulate fraction (PF) constituted approximately 80% of cellular PP-1 activity, while PP-2A was entirely cytosolic.
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23 |
7822300
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Insulin rapidly stimulated PF PP-1 in a time- and dose-dependent manner (maximum stimulation at 5 min with 4 nM insulin).
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24 |
7822300
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Immunoprecipitation of PF with an antibody against the site-1 sequence of rabbit skeletal muscle glycogen-associated PP-1 (PP-1G) subunit indicated that approximately 40% of adipocyte PP-1 activity was due to PP-1G form of the enzyme.
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25 |
7822300
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Insulin stimulated PP-1G (120% over basal levels) without affecting the other forms of PP-1 in the PF.
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26 |
7822300
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Insulin activation of PP-1 was accompanied by > 2-fold increase in the phosphorylation state of the 160-kDa regulatory subunit of PP-1.
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27 |
7822300
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Stimulation of p21Ras/mitogen-activated protein kinase pathway (MAP) with GTP analogues also resulted in stimulation of PP-1 similar to insulin.
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28 |
7822300
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The insulin effect on MAP kinase and PP-1 activation was blocked by a GTP antagonist, guanyl-5'-yl thiophosphate.
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29 |
7822300
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The inhibitors of MAP kinase activation (viz. cAMP agonists, SpcAMP and ML-9) also blocked PP-1 stimulation by insulin.
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30 |
7822300
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The time course of MAP kinase activation preceded the phosphorylation of PP-1 regulatory subunit and PP-1 activation.
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31 |
7822300
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We conclude that insulin rapidly activates a membrane-associated PP-1 in adipocytes, which may be similar to rabbit skeletal muscle PP-1G, and the activation is mediated by p21Ras/MAP kinase pathway.
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32 |
8663361
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Okadaic acid exerts a full insulin-like effect on glucose transport and glucose transporter 4 translocation in human adipocytes.
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33 |
8663361
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The effects of the serine/threonine phosphatase inhibitor, okadaic acid, and insulin on glucose transport activity, glucose transporter 4 translocation to the plasma membrane, and the signaling pathway of insulin were examined in human adipocytes.
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34 |
8663361
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Both insulin alone and okadaic acid alone stimulated the translocation of glucose transporter 4 to the plasma membrane.
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35 |
8663361
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Insulin, but not okadaic acid, stimulated phosphatidylinositol 3-kinase (PI 3-kinase) activity, and wortmannin completely inhibited the effect of insulin on glucose transport.
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36 |
8663361
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When the cells were incubated with both agents, okadaic acid inhibited insulin-stimulated PI 3-kinase activity but did not block the association of the p85 or p110 subunits of PI 3-kinase with insulin receptor substrate 1.
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37 |
8663361
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Insulin-stimulated tyrosine phosphorylation of insulin receptor substrate 1 was only slightly reduced (15-30%) by okadaic acid.
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38 |
8665940
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Effect of tumor necrosis factor-alpha on insulin-stimulated mitogen-activated protein kinase cascade in cultured rat skeletal muscle cells.
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39 |
8665940
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Tumor necrosis factor-alpha (TNF-alpha) is a proposed mediator of insulin resistance in obese/diabetic animals through its effects on tyrosine phosphorylation of the insulin receptor and its substrate, insulin receptor substrate-1.
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40 |
8665940
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In this study, the acute effects of TNF-alpha on the mitogen-activated protein kinase (MAPK) signalling cascade were examined in cultured rat skeletal muscle cell line, L6.
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41 |
8665940
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Insulin treatment of L6 cells resulted in a rapid increase in MAPK activity (> twofold in 5 min with 10 nM insulin).
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42 |
8665940
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Prior treatment with TNF-alpha for 60 min blocked subsequent insulin-induced activation of MAPK in a dose- and time-dependent manner.
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43 |
8665940
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Metabolic labelling studies with inorganic [32P]phosphate followed by immuno-precipitation of MAPK and its upstream activator, mitogen-activated protein kinase kinase, indicated decreased phosphorylation of MAPK and its kinase in response to insulin in cells exposed to TNF-alpha.
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44 |
8665940
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This effect of TNF-alpha was not due to inhibition of insulin-stimulated p21ras-GTP loading or Raf-1 phosphorylation.
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45 |
8665940
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Low concentrations (2 nM) of okadaic acid, a serine/threonine phosphatase inhibitor, prevented TNF-alpha-induced inhibition of MAPK and restored insulin's effect on MAPK activity, while orthovanadate (a tyrosine phosphatase inhibitor), inhibitor 2 (phosphatase-1 inhibitor) and FK506 (phosphatase-2B inhibitor) were ineffective.
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46 |
8665940
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These results suggested an involvement of an okadaic-acid-sensitive serine/threonine phosphatase in TNF-alpha-induced blockade of insulin's effect on MAPK and/or its kinase.
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47 |
8665940
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Therefore, we examined the effect of TNF-alpha on protein phosphatase-1 (PP-1) and protein phosphatase-2A (PP-2A) activities.
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48 |
8665940
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As reported by us earlier, insulin rapidly stimulated PP-1 and concomitantly inhibited PP-2A activities in control cells.
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49 |
8665940
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TNF-alpha treatment blocked insulin-induced activation of PP-1.
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50 |
8665940
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In contrast to PP-1, TNF-alpha caused a 60% increase in PP-2A activity and insulin failed to prevent this TNF-alpha effect.
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51 |
8665940
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The time course of PP-2A activation by TNF-alpha preceded the kinetics of inhibition of MAPK.
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52 |
8665940
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Cell-permeable ceramide analogs mimicked the TNF-alpha effect on MAPK inhibition and PP-2A activation.
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53 |
8665940
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We conclude that TNF-alpha abrogates the insulin effect on MAPK activation by increasing dephosphorylation of MAPK kinase via an activated phosphatase.
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54 |
8665940
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Effect of tumor necrosis factor-alpha on insulin-stimulated mitogen-activated protein kinase cascade in cultured rat skeletal muscle cells.
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55 |
8665940
|
Tumor necrosis factor-alpha (TNF-alpha) is a proposed mediator of insulin resistance in obese/diabetic animals through its effects on tyrosine phosphorylation of the insulin receptor and its substrate, insulin receptor substrate-1.
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56 |
8665940
|
In this study, the acute effects of TNF-alpha on the mitogen-activated protein kinase (MAPK) signalling cascade were examined in cultured rat skeletal muscle cell line, L6.
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57 |
8665940
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Insulin treatment of L6 cells resulted in a rapid increase in MAPK activity (> twofold in 5 min with 10 nM insulin).
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58 |
8665940
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Prior treatment with TNF-alpha for 60 min blocked subsequent insulin-induced activation of MAPK in a dose- and time-dependent manner.
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59 |
8665940
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Metabolic labelling studies with inorganic [32P]phosphate followed by immuno-precipitation of MAPK and its upstream activator, mitogen-activated protein kinase kinase, indicated decreased phosphorylation of MAPK and its kinase in response to insulin in cells exposed to TNF-alpha.
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60 |
8665940
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This effect of TNF-alpha was not due to inhibition of insulin-stimulated p21ras-GTP loading or Raf-1 phosphorylation.
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61 |
8665940
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Low concentrations (2 nM) of okadaic acid, a serine/threonine phosphatase inhibitor, prevented TNF-alpha-induced inhibition of MAPK and restored insulin's effect on MAPK activity, while orthovanadate (a tyrosine phosphatase inhibitor), inhibitor 2 (phosphatase-1 inhibitor) and FK506 (phosphatase-2B inhibitor) were ineffective.
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62 |
8665940
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These results suggested an involvement of an okadaic-acid-sensitive serine/threonine phosphatase in TNF-alpha-induced blockade of insulin's effect on MAPK and/or its kinase.
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63 |
8665940
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Therefore, we examined the effect of TNF-alpha on protein phosphatase-1 (PP-1) and protein phosphatase-2A (PP-2A) activities.
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64 |
8665940
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As reported by us earlier, insulin rapidly stimulated PP-1 and concomitantly inhibited PP-2A activities in control cells.
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65 |
8665940
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TNF-alpha treatment blocked insulin-induced activation of PP-1.
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66 |
8665940
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In contrast to PP-1, TNF-alpha caused a 60% increase in PP-2A activity and insulin failed to prevent this TNF-alpha effect.
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67 |
8665940
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The time course of PP-2A activation by TNF-alpha preceded the kinetics of inhibition of MAPK.
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68 |
8665940
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Cell-permeable ceramide analogs mimicked the TNF-alpha effect on MAPK inhibition and PP-2A activation.
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69 |
8665940
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We conclude that TNF-alpha abrogates the insulin effect on MAPK activation by increasing dephosphorylation of MAPK kinase via an activated phosphatase.
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70 |
8679660
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Cryptic receptors for insulin-like growth factor II in the plasma membrane of rat adipocytes--a possible link to cellular insulin resistance.
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71 |
8679660
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To further elucidate the mechanisms for short-term regulation of the receptor for insulin-like growth factor II (IGF-II), we investigated effects of insulin, cAMP and phosphatase inhibitors on cell surface 125I-IGF-II binding in rat adipocytes.
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72 |
8679660
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Preincubation with the serine/threonine phosphatase inhibitor okadaic acid (OA, 1 microM) or the non-hydrolysable cAMP analogue N6-mbcAMP (4 mM) markedly impaired insulin-stimulated 125I-IGF-II binding.
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73 |
8679660
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Phospholipase C (PLC), which cleaves phospholipids at the cell surface, markedly enhanced cell surface 125I-IGF-II binding in a concentration-dependent manner.
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74 |
8679660
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Scatchard analysis demonstrated that the effect of PLC was due to an increased number of binding sites suggesting that "cryptic' IGF-II receptors are associated with the plasma membrane (PM).
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75 |
8679660
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PLC (5 U/ml) also reversed the N6-mbcAMP-induced decrease of 125I-IGF-II binding at a low insulin concentration (10 microU/ml).
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76 |
8679660
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Taken together, these data indicate that cAMP, similar to its effects on the glucose transporter GLUT 4 and the insulin receptor, may increase the proportion of functionally cryptic IGF-II receptors in the PM through mechanisms involving serine phosphorylation, possibly of a docking or coupling protein.
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77 |
8972717
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The serine/threonine phosphatase inhibitor, okadaic acid (OA), exerted several insulin-like effects in rat adipose cells and was, in part, synergistic with insulin.
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78 |
8972717
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OA stimulated glucose transport activity, altered the electrophoretic mobility of IRS-1, increased the phosphorylation of the MAP-kinases ERK 1 and 2 on tyrosine sites, markedly increased MAP kinase activity and also acted synergistically with insulin in activating these enzymes.
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79 |
8972717
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Staurosporine virtually completely inhibited the insulin-stimulated glucose transport and MAP kinase activation in spite of a maintained high PI 3-kinase activity.
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80 |
9002993
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The addition of phospholipase C (from Clostridium perfringens), which cleaves PM phospholipids, mimicked the effect of insulin to enhance cell surface binding in adipocytes, and this suggests a pool of cryptic PM receptors.
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81 |
9002993
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Both the nonmetabolizable cAMP analog N6-monobutyryl cAMP (N6-mbcAMP) and the serine/threonine phosphatase inhibitor okadaic acid abolished the effect of concomitant insulin treatment to increase binding capacity.
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82 |
9166680
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Loci included the G-protein-coupled inwardly rectifying potassium channels expressed in beta-cells (KCNJ3 and KCNJ7), glucagon (GCG), glucokinase regulatory protein (GCKR), glucagon-like peptide I receptor (GLP1R), LIM/homeodomain islet-1 (ISL1), caudal-type homeodomain 3 (CDX3), proprotein convertase 2 (PCSK2), cholecystokinin B receptor (CCKBR), hexokinase 1 (HK1), hexokinase 2 (HK2), mitochondrial FAD-glycerophosphate dehydrogenase (GPD2), liver and muscle forms of pyruvate kinase (PKL, PKM), fatty acid-binding protein 2 (FABP2), hepatic phosphofructokinase (PFKL), protein serine/threonine phosphatase 1 beta (PPP1CB), and low-density lipoprotein receptor (LDLR).
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83 |
11341829
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Small molecule peptidomimetics containing a novel phosphotyrosine bioisostere inhibit protein tyrosine phosphatase 1B and augment insulin action.
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84 |
11341829
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Protein tyrosine phosphatase 1B (PTP1B) attenuates insulin signaling by catalyzing dephosphorylation of insulin receptors (IR) and is an attractive target of potential new drugs for treating the insulin resistance that is central to type II diabetes.
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85 |
11341829
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Several analogues of cholecystokinin(26)(-)(33) (CCK-8) were found to be surprisingly potent inhibitors of PTP1B, and a common N-terminal tripeptide, N-acetyl-Asp-Tyr(SO(3)H)-Nle-, was shown to be necessary and sufficient for inhibition.
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86 |
11341829
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This led to the discovery of a novel phosphotyrosine bioisostere, 2-carboxymethoxybenzoic acid, and to analogues that were >100-fold more potent than the CCK-8 analogues and >10-fold selective for PTP1B over two other PTP enzymes (LAR and SHP-2), a dual specificity phosphatase (cdc25b), and a serine/threonine phosphatase (calcineurin).
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87 |
11341829
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In some instances, PTP1B inhibitors were insulin-mimetic, suggesting that in unstimulated cells PTP1B may suppress basal IRTK activity.
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88 |
11341829
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These CCK-derived peptidomimetic inhibitors of PTP1B represent a novel template for further development of potent, selective inhibitors, and their cell activity further justifies the selection of PTP1B as a therapeutic target.
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89 |
16907705
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The product of the PPP1R3B gene (G(L)) is the regulatory subunit of PP1 - a serine/threonine phosphatase involved in the modulation of glycogen synthesis in the liver and skeletal muscle.
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90 |
18771283
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The TPR proteins FKBP52, FKBP51, Cyp40, and PP5 are found in steroid receptor (SR) complexes, but their receptor-specific preferences and roles remain unresolved.
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91 |
18771283
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The GR of L929 cells was found in the cytoplasm in a complex containing PP5 and FKBP51, while the GR of WCL2 cells was nuclear and contained PP5 and FKBP52.
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92 |
18771283
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Similar to L929 cells, the GR in COS interacted with PP5 and FKBP51, while PR interacted with FKBP52.
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93 |
18771283
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PR in FKBP52 KO cells showed a complete shift to the cytoplasm, while GR in FKBP51 KO and PP5 KO cells showed a moderate shift to the nucleus, indicating that both TPRs contribute to GR localization.
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94 |
18771283
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The TPR proteins FKBP52, FKBP51, Cyp40, and PP5 are found in steroid receptor (SR) complexes, but their receptor-specific preferences and roles remain unresolved.
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95 |
18771283
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The GR of L929 cells was found in the cytoplasm in a complex containing PP5 and FKBP51, while the GR of WCL2 cells was nuclear and contained PP5 and FKBP52.
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96 |
18771283
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Similar to L929 cells, the GR in COS interacted with PP5 and FKBP51, while PR interacted with FKBP52.
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97 |
18771283
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PR in FKBP52 KO cells showed a complete shift to the cytoplasm, while GR in FKBP51 KO and PP5 KO cells showed a moderate shift to the nucleus, indicating that both TPRs contribute to GR localization.
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98 |
18771283
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The TPR proteins FKBP52, FKBP51, Cyp40, and PP5 are found in steroid receptor (SR) complexes, but their receptor-specific preferences and roles remain unresolved.
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99 |
18771283
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The GR of L929 cells was found in the cytoplasm in a complex containing PP5 and FKBP51, while the GR of WCL2 cells was nuclear and contained PP5 and FKBP52.
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100 |
18771283
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Similar to L929 cells, the GR in COS interacted with PP5 and FKBP51, while PR interacted with FKBP52.
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101 |
18771283
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PR in FKBP52 KO cells showed a complete shift to the cytoplasm, while GR in FKBP51 KO and PP5 KO cells showed a moderate shift to the nucleus, indicating that both TPRs contribute to GR localization.
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102 |
21994940
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Protein phosphatase 5 mediates lipid metabolism through reciprocal control of glucocorticoid receptor and peroxisome proliferator-activated receptor-γ (PPARγ).
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103 |
21994940
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In response to adipogenic stimuli, PP5-KO mouse embryonic fibroblast cells showed almost no lipid accumulation with reduced expression of adipogenic markers (aP2, CD36, and perilipin) and low fatty-acid synthase enzymatic activity.
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104 |
22728334
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Protein phosphatase 1 regulatory subunit 12A and catalytic subunit δ, new members in the phosphatidylinositide 3 kinase insulin-signaling pathway.
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105 |
22728334
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Numerous studies have focused on kinases in IRS1 phosphorylation and insulin resistance; however, the mechanism for serine/threonine phosphatase action in insulin signaling is largely unknown.
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106 |
22728334
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Recently, we identified protein phosphatase 1 (PP1) regulatory subunit 12A (PPP1R12A) as a novel endogenous insulin-stimulated interaction partner of IRS1 in L6 myotubes.
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107 |
22728334
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Insulin stimulation promoted an interaction between the IRS1/p85 complex and PPP1R12A; however, p85 and PPP1R12A did not interact independent of IRS1.
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108 |
22728334
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Moreover, kinase inhibition experiments indicated that insulin-induced interaction between IRS1 and PPP1R12A was reduced by treatment with inhibitors of phosphatidylinositide 3 kinase, PDK1, Akt, and mTOR/raptor but not MAPK.
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109 |
22728334
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Furthermore, a novel insulin-stimulated IRS1 interaction partner, PP1 catalytic subunit (PP1cδ), was identified, and its interaction with IRS1 was also disrupted by inhibitors of Akt and mTOR/raptor.
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110 |
22728334
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These results indicate that PPP1R12A and PP1cδ are new members of the insulin-stimulated IRS1 signaling complex, and the interaction of PPP1R12A and PP1cδ with IRS1 is dependent on Akt and mTOR/raptor activation.
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111 |
22728334
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These findings provide evidence for the involvement of a particular PP1 complex, PPP1R12A/PP1cδ, in insulin signaling and may lead to a better understanding of dysregulated IRS1 phosphorylation in insulin resistance and T2D.
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112 |
22814597
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In this issue of Developmental Cell, Goodyer et al. (2012) reveal a function of calcineurin, a calcium-activated serine/threonine phosphatase, in postnatal NFATc-regulated expression of genes that help β cells to form insulin-containing vesicles and enter the cell cycle.
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