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Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Structure-based design and synthesis of the 3,4'-bispyridinylethylene series led to the discovery of 3-isoquinolinylpyridine 13a as a potent
PKB
/Akt inhibitor with an IC(50) of 1.3nM against Akt1. Compound 13a shows excellent selectivity against distinct families of kinases such as tyrosine kinases and CAMK, and displays poor to marginal selectivity against closely related kinases in the AGC and CMGC families. Moreover, 13a demonstrates potent cellular activity comparable to staurosporine, with IC(50) values of 0.42 and 0.59microM against MiaPaCa-2 and the Akt1 overexpressing FL5.12-Akt1, respectively. Inhibition of phosphorylation of the Akt downstream target
GSK3
was also observed in FL5.12-Akt1 cells with an EC(50) of 1.5microM. The X-ray structures of 12 and 13a in complex with PKA in the ATP-binding site were determined.
...
PMID:Synthesis and structure-activity relationship of 3,4'-bispyridinylethylenes: discovery of a potent 3-isoquinolinylpyridine inhibitor of protein kinase B (PKB/Akt) for the treatment of cancer. 1641 80
We examined the role for the JAK/STAT signaling pathway in acute opioid-induced cardioprotection (OIC) and whether opioid-induced glycogen synthase kinase-3beta (
GSK-3 beta
) inhibition is mediated by the JAK/STAT pathway. Rats underwent 30 min of ischemia and either 5 min or 2 h of reperfusion, followed by tissue isolation for molecular analysis or infarct size assessment, respectively. Rats were treated with vehicle, morphine (300 microg/kg), the delta-opioid agonist fentanyl isothiocynate (FIT, 10 microg/kg), or the GSK inhibitor SB-216763 (SB21, 600 microg/kg) 10 min before ischemia. Five minutes before opioid or SB21 treatment, some rats received the putative
JAK2
inhibitor AG-490 (3 mg/kg) or the putative
JAK3
inhibitor ZM-449829 (3 mg/kg). H9C2 cardiomyoblast cells were also used to investigate FIT-induced signaling (1 microM) in vitro via molecular analysis. Morphine induced the phosphorylation of
JAK2
, yet not
JAK1
, in the area at risk. Morphine, FIT, and SB21 also reduced infarct size compared with vehicle (water) when administered before ischemia [43.0 +/- 2.8, 39.1 +/- 3.1, and 42.1 +/- 2.5 (*P < 0.001, respectively) vs. 58.1 +/- 1.3%, respectively]. AG-490 abrogated OIC, whereas ZM-449829 had no effect on OIC. Cardioprotection was afforded by SB21 even in the presence of AG-490. Morphine phosphorylated STAT3, Akt, and GSK-3beta, and phosphorylation was abrogated by AG-490. FIT stimulation of H9C2 cells also caused a time-dependent phosphorylation of STAT3, Akt, and GSK-3beta, and this effect was abrogated by AG-490. STAT3 phosphorylation was also dependent on phosphatidylinositol 3-kinase (PI3K) activation in both tissue and H9C2 cells. These data suggest that OIC occurs via the
JAK2
regulation of PI3K pathway-dependent STAT3, Akt, and
GSK-3 beta
, with
GSK-3 beta
contributing a central role in acute OIC.
...
PMID:The JAK/STAT pathway is essential for opioid-induced cardioprotection: JAK2 as a mediator of STAT3, Akt, and GSK-3 beta. 1651 48
Activation of PKCtheta is associated with lipid-induced insulin resistance and PKCtheta knockout mice are protected from the lipid-induced defects. However, the exact mechanism by which PKCtheta contributes to insulin resistance is not known. To investigate whether an increase in PKCtheta expression leads to insulin resistance, C2C12 skeletal muscle cells were transfected with PKCtheta DNA and treated with different concentrations of insulin for 10 min. PKCtheta overexpression induced reduction of IRS-1 protein levels with a decrease in insulin-induced p85 binding to IRS-1, phosphorylation of
PKB
and its substrates, p70 and
GSK3
. Pretreatment of these cells with GF-109203X (a non-specific PKC inhibitor, IC50 for PKCtheta = 10 nM) recovered insulin signaling. PKCtheta was found to be expressed in liver and treatment of human hepatoma cells (HepG2) with high insulin and glucose resulted in an increase in PKCtheta expression that correlated with a decrease in IRS-1 protein levels and the development of insulin resistance. Reduction of PKCtheta expression using RNAi technology significantly inhibited the degradation of IRS-1 and enhanced insulin-induced IRS-1 tyrosine phosphorylation, p85 association to IRS-1 and
PKB
phosphorylation. In conclusion, by overexpressing PKCtheta or using RNAi technology to downregulate PKCtheta, we have demonstrated that PKCtheta has a key role in the development of insulin resistance. These findings suggest that PKCtheta mediates not only insulin resistance in muscle but also in liver, which may contribute to the development of whole body insulin resistance and diabetes.
...
PMID:PKCtheta is a key player in the development of insulin resistance. 1654 76
Mammalian target of rapamycin (mTOR) controls cell growth and proliferation via the raptor-mTOR (TORC1) and rictor-mTOR (TORC2) protein complexes. Recent biochemical studies suggested that TORC2 is the elusive PDK2 for Akt/
PKB
Ser473 phosphorylation in the hydrophobic motif. Phosphorylation at Ser473, along with Thr308 of its activation loop, is deemed necessary for Akt function, although the regulatory mechanisms and physiological importance of each phosphorylation site remain to be fully understood. Here, we report that SIN1/MIP1 is an essential TORC2/PDK2 subunit. Genetic ablation of sin1 abolished Akt-Ser473 phosphorylation and disrupted rictor-mTOR interaction but maintained Thr308 phosphorylation. Surprisingly, defective Ser473 phosphorylation affected only a subset of Akt targets in vivo, including FoxO1/3a, while other Akt targets, TSC2 and
GSK3
, and the TORC1 effectors, S6K and 4E-BP1, were unaffected. Our findings reveal that the SIN1-rictor-mTOR function in Akt-Ser473 phosphorylation is required for TORC2 function in cell survival but is dispensable for TORC1 function.
...
PMID:SIN1/MIP1 maintains rictor-mTOR complex integrity and regulates Akt phosphorylation and substrate specificity. 1696 53
PKCdelta has been shown to be activated by insulin and to interact with insulin receptor and IRS.
PKB
(Akt) plays an important role in glucose transport and glycogen synthesis. In this study, we investigated the possibility that PKCdelta may be involved in insulin-induced activation of
PKB
. Studies were conducted on primary cultures of rat skeletal muscle.
PKB
was activated by insulin stimulation within 5min and reached a peak by 15-30min. Insulin also increased the physical association between PKCdelta with
PKB
and with PDK1. The insulin-induced PKCdelta-
PKB
association was PI3K dependent.
PKB
-PKCdelta association was accounted for by the involvement of PDK1. Overexpression of dominant negative PKCdelta abrogated insulin-induced association of PKCdelta with both
PKB
and PDK1. Blockade of PKCdelta also decreased insulin-induced Thr308
PKB
phosphorylation and
PKB
translocation. Moreover, PKCdelta inhibition reduced insulin-induced
GSK3
phosphorylation. The results indicate that insulin-activated PKCdelta interacts with PDK1 to regulate
PKB
.
...
PMID:Protein kinase Cdelta participates in insulin-induced activation of PKB via PDK1. 1696 99
The specificities of 65 compounds reported to be relatively specific inhibitors of protein kinases have been profiled against a panel of 70-80 protein kinases. On the basis of this information, the effects of compounds that we have studied in cells and other data in the literature, we recommend the use of the following small-molecule inhibitors: SB 203580/SB202190 and BIRB 0796 to be used in parallel to assess the physiological roles of p38 MAPK (mitogen-activated protein kinase) isoforms, PI-103 and wortmannin to be used in parallel to inhibit phosphatidylinositol (phosphoinositide) 3-kinases, PP1 or PP2 to be used in parallel with Src-I1 (Src inhibitor-1) to inhibit Src family members; PD 184352 or PD 0325901 to inhibit MKK1 (MAPK kinase-1) or MKK1 plus MKK5, Akt-I-1/2 to inhibit the activation of
PKB
(protein kinase B/Akt), rapamycin to inhibit TORC1 [mTOR (mammalian target of rapamycin)-raptor (regulatory associated protein of mTOR) complex], CT 99021 to inhibit
GSK3
(glycogen synthase kinase 3), BI-D1870 and SL0101 or FMK (fluoromethylketone) to be used in parallel to inhibit RSK (ribosomal S6 kinase), D4476 to inhibit CK1 (casein kinase 1), VX680 to inhibit Aurora kinases, and roscovitine as a pan-CDK (cyclin-dependent kinase) inhibitor. We have also identified harmine as a potent and specific inhibitor of DYRK1A (dual-specificity tyrosine-phosphorylated and -regulated kinase 1A) in vitro. The results have further emphasized the need for considerable caution in using small-molecule inhibitors of protein kinases to assess the physiological roles of these enzymes. Despite being used widely, many of the compounds that we analysed were too non-specific for useful conclusions to be made, other than to exclude the involvement of particular protein kinases in cellular processes.
...
PMID:The selectivity of protein kinase inhibitors: a further update. 1785 Feb 14
Inhibition of glycogen synthase kinase 3beta (GSK3beta) as a consequence of its phosphorylation by protein kinase B/Akt (
PKB
/Akt) has been implicated in cardiac myocyte hypertrophy in response to endothelin-1 or phenylephrine. We examined the regulation of GSK3alpha (which we show to constitute a significant proportion of the myocyte
GSK3
pool) and GSK3beta in cardiac myocytes. Although endothelin increases phosphorylation of
GSK3
and decreases its activity, the response is less than that induced by insulin (which does not promote cardiac myocyte hypertrophy).
GSK3
phosphorylation induced by endothelin requires signalling through the extracellular signal-regulated kinase 1/2 (ERK1/2) cascade and not the
PKB
/Akt pathway, whereas the reverse is true for insulin. Cardiac myocyte hypertrophy involves changes in morphology, and in gene and protein expression. The potent
GSK3
inhibitor 1-azakenpaullone increases myocyte area as a consequence of increased cell length whereas phenylephrine increases both length and width. Azakenpaullone or insulin promotes AP1 transcription factor binding to an AP1 consensus oligonucleotide, but this was significantly less than that induced by endothelin and derived principally from increased binding of JunB protein, the expression of which was increased. Azakenpaullone promotes significant changes in gene expression (assessed by Affymetrix microarrays), but the overall response is less than with endothelin and there is little overlap between the genes identified. Thus, although
GSK3
may contribute to cardiac myocyte hypertrophy in some respects (and presumably plays an important role in myocyte metabolism), it does not appear to contribute as significantly to the response induced by endothelin as has been maintained.
...
PMID:Glycogen synthase kinases 3alpha and 3beta in cardiac myocytes: regulation and consequences of their inhibition. 1799 64
Glycogen synthase kinase 3 (
GSK3
, of which there are two isoforms, GSK3alpha and GSK3beta) was originally characterized in the context of regulation of glycogen metabolism, though it is now known to regulate many other cellular processes. Phosphorylation of GSK3alpha(Ser21) and GSK3beta(Ser9) inhibits their activity. In the heart, emphasis has been placed particularly on GSK3beta, rather than GSK3alpha. Importantly, catalytically-active
GSK3
generally restrains gene expression and, in the heart, catalytically-active
GSK3
has been implicated in anti-hypertrophic signalling. Inhibition of
GSK3
results in changes in the activities of transcription and translation factors in the heart and promotes hypertrophic responses, and it is generally assumed that signal transduction from hypertrophic stimuli to
GSK3
passes primarily through protein kinase B/Akt (
PKB
/Akt). However, recent data suggest that the situation is far more complex. We review evidence pertaining to the role of
GSK3
in the myocardium and discuss effects of genetic manipulation of
GSK3
activity in vivo. We also discuss the signalling pathways potentially regulating
GSK3
activity and propose that, depending on the stimulus, phosphorylation of
GSK3
is independent of
PKB
/Akt. Potential
GSK3
substrates studied in relation to myocardial hypertrophy include nuclear factors of activated T cells, beta-catenin, GATA4, myocardin, CREB, and eukaryotic initiation factor 2Bvarepsilon. These and other transcription factor substrates putatively important in the heart are considered. We discuss whether cardiac pathologies could be treated by therapeutic intervention at the
GSK3
level but conclude that any intervention would be premature without greater understanding of the precise role of
GSK3
in cardiac processes.
...
PMID:Glycogen synthase kinase 3 (GSK3) in the heart: a point of integration in hypertrophic signalling and a therapeutic target? A critical analysis. 1820 89
Kinex antibody microarray analyses was used to investigate the regulation of 188 protein kinases, 24 protein phosphatases, and 170 other regulatory proteins during meiotic maturation of immature germinal vesicle (GV+) pig oocytes to maturing oocytes that had completed meiosis I (MI), and fully mature oocytes arrested at metaphase of meiosis II (MII). Increases in apparent protein levels of protein kinases accounted for most of the detected changes during the GV to MI transition, whereas reduced protein kinase levels and increased protein phosphorylation characterized the MI to MII transition. During the MI to MII period, many of the MI-associated increased levels of the proteins and phosphosites were completely or partially reversed. The regulation of these proteins were also examined in parallel during the meiotic maturation of bovine, frog, and sea star oocytes with the Kinex antibody microarray. Western blotting analyses confirmed altered expression levels of Bub1A, IRAK4, MST2, PP4C, and Rsk2, and the phosphorylation site changes in the kinases Erk5 (T218 + Y220),
FAK
(S722),
GSK3
-beta (Y216), MEK1 (S217 + S221) and PKR1 (T451), and nucleophosmin/B23 (S4) during pig oocyte maturation.
...
PMID:Antibody microarray analyses of signal transduction protein expression and phosphorylation during porcine oocyte maturation. 1848 64
Protein kinase B (
PKB
; also known as Akt) is important for mediating survival and proliferation signals. Following activation,
PKB
shuttles to various compartments of the cell, including the nucleus, where it phosphorylates an array of targets.
PKB
is phosphorylated at T308 by its activator PDK1. PDK1 is normally excluded from the nucleus via a nuclear exclusion sequence (NES), and our previous work suggested that nuclear exclusion can be attenuated by IGF-1-induced phosphorylation of S396 proximal to the NES. No studies have been done to test the significance of S396 phosphorylation or the impact of nuclear accumulation of PDK1 on
PKB
activation. To address these questions, we created isogenic embryonic stem cell (ESC) lines expressing various alleles of PDK1 within a PDK1-/- background. Disruption of the NES domain of PDK1 correlated with elevated
PKB
phosphorylation at both T308 and S473. In contrast, mutation of S396 to alanine reduced PDK1 nuclear localization and reduced
PKB
phosphorylation and activation. The loss of phosphorylation of
PKB
by S396A mutation was rescued by forcing nuclear PDK1 or by conversion of S396 to an aspartic acid. The phosphorylation of the
PKB
substrate FOXO3alpha was reduced in S396A PDK1 ESC. Other known and suspected
PKB
substrates, including
GSK3
and Raf1, were unaffected. This study therefore reveals that S396 plays a role in the activation of
PKB
leading to the regulated phosphorylation of some
PKB
substrates including FOXO3alpha.
...
PMID:Serine 396 of PDK1 is required for maximal PKB activation. 1871 28
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