Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human promyelocytic leukemia cell line HL-60 was induced to differentiate to mature granulocytic cells by dbcAMP or RA. The influence of distinct protein kinases during different stages of this differentiation was studied by the use of H8, staurosporine and genistein as inhibitors of PKA, PKC and PTK respectively. In dbcAMP-mediated differentiation, the PKA activity of uninduced cells is crucial for the induction of differentiation, but therefore its significance drastically declines and a more important role is played by PKC and PTK. In RA-mediated differentiation, the native state of PKA and PKC activities are necessary and of similar importance for induction. However, the differentiation is enhanced when, following induction, the activities of PKA and PTK are normal and the activity of PKC, in contrast, is temporary suppressed. At the phenotypic stage the effect of inhibition of protein kinases on maturation is in the order PTK > PKC > PKA for the dbcAMP-mediated differentiation and PKC > PKA > PTK for the RA-mediated differentiation. The results indicate that protein kinase activities during differentiation are stage specific and this specificity depends on the inducer used.
 ...
PMID:Protein kinase inhibitors exert stage specific and inducer dependent effects on HL-60 cell differentiation. 764 44

Thrombin stimulates synthesis and secretion of endothelin-1 (ET-1), a vasoactive peptide that triggers responses in the vascular endothelium and smooth muscle. We investigated the signal transduction pathways by which thrombin stimulates preproET-1 gene expression and ET-1 peptide secretion in macrovascular cells (human umbilical vein endothelial cells [HUVECs] and bovine pulmonary artery endothelial cells [BPAECs]) and microvascular cells (human microvascular endothelial cell line [HMEC-1]). Thrombin (4 U/mL) stimulated maximal induction of ET-1 peptide secretion and preproET-1 mRNA after 2 hours in HUVECs and BPAECs and after 1 hour in HMEC-1. A synthetic thrombin receptor activator peptide confirmed ligand-specific receptor actions to induce preproET-1 mRNA. Protein kinase C (PKC) activation by phorbol ester transiently induced preproET-1 mRNA but had no effect on ET-1 peptide synthesis. PKC inhibitors sangivamycin and calphostin C and PKC depletion failed to suppress thrombin-stimulated preproET-1 mRNA. Adenylate cyclase and cAMP-dependent protein kinase did not participate in thrombin-induced preproET-1 gene activation. Thrombin stimulated a rapid increase in phosphotyrosine-containing proteins, suggesting a role for tyrosine phosphorylation in thrombin signaling. These data demonstrate that thrombin induces the preproET-1 gene and ET-1 peptide synthesis by a PKC-independent PTK-dependent pathway in macrovascular and microvascular endothelial cells. Protein tyrosine kinase inhibitors herbimycin A and genistein blocked thrombin-stimulated preproET-1 mRNA and peptide secretion, whereas daidzein, which lacks inhibitory activity, did not suppress thrombin-induced ET-1.
 ...
PMID:Thrombin induces the preproendothelin-1 gene in endothelial cells by a protein tyrosine kinase-linked mechanism. 775 70

The role of different protein kinases in the process of T cell activation has been studied using several inhibitors. The model we adopted was the activation of PBMC by monoclonal antibody OKT3. The results obtained confirm that PKC and PTK are involved. Thus, the inhibitors H-7, staurosporine, and genistein exerted a dose-dependent inhibition of CD2 up-regulation, CD25 expression, IL-2 production, and cellular proliferation. On the other hand, our data indicate that PKA is not involved since the inhibitor HA1004 was ineffective. W-7, an inhibitor of Ca(2+)-CaM protein kinases, inhibited OKT3-induced modulation of cell-surface markers and PBMC proliferation, whereas a slight increase in IL-2 release was detected at the highest dose used (20 microM). Using the MLCK inhibitor ML-9, we extended our studies to the myosin light chain kinase, which influences the organization of the cytoskeleton. ML-9-inhibited PBMC activation in terms of modulation of cell-surface markers and proliferation but stimulated IL-2 production. Similar results were obtained using the cytoskeleton disruptors demecolcine and cytochalasin B. Taken together the data described herein indicate that T cell activation is a complex event in which, aside from classical signal transduction-associated kinases PKC and PTK, at least two other kinases, Ca(2+)-CaM kinases and MLCK, seem to be involved, the latter probably through correct assembly of the cytoskeleton.
 ...
PMID:Involvement of multiple protein kinases in CD3-mediated activation of human T lymphocytes. 790 41

We have previously demonstrated that activation of cAMP-dependent protein kinase (cAK) type I (cAKI, RI alpha 2-C beta 2) mediates the inhibitory effects of cAMP on T-cell replication induced through the TCR/CD3 complex. In the present study we have investigated the effect of cAMP on T-cell DNA synthesis, tyrosine phosphorylation of a 100 kDa protein (pp100) and IL2 mRNA expression, induced through stimulation of the TCR/CD3- and/or the CD28 molecules. Our results demonstrate that tyrosine phosphorylation of pp100 stimulated by anti-CD3 is inhibited by cAMP both in the presence and absence of the phorbol ester PMA, and reflects the changes seen in IL2 mRNA expression and T-cell replication. Combined stimulation with anti-CD3 and anti-CD28, which gives a synergistic response in T-cell replication, gave pp100 phosphorylation and IL2 mRNA expression sensitive to cAMP-dependent inhibition. When PMA was added in addition to anti-CD3 and anti-CD28, the inhibitory effect of cAMP on both T-cell replication and pp100 phosphorylation was completely abolished. The fact that pp100 phosphorylation in response to TCR/CD3-, CD28- and PMA stimulation and cAMP mediated inhibition are identical to the effects of the same stimuli on T-cell proliferation, makes this protein an interesting candidate in downstream signalling from these receptors. In addition, our results are compatible with a model where cAMP, through activation of cAKI, eliminates both the PTK and PKC activating capability of the T-cell receptor at a site(s) proximal to PKC activation. Furthermore, the CD28 molecule which activates PTKs, enters the PTK cascade at a point distal to the target(s) for cAKI action. Therefore, during CD28 signalling PKC activation can be achieved either by TCR/CD3 stimulation (inhibited by cAMP), or directly by PMA (not inhibited by cAMP).
 ...
PMID:Cyclic AMP sensitive signalling by the CD28 marker requires concomitant stimulation by the T-cell antigen receptor (TCR/CD3) complex. 804 42

Tumor necrosis factor-alpha (TNF) induces clustering of theca-interstitial cells (TIC) isolated from immature, hypophysectomized rats, while inhibiting luteinizing hormone (LH)-stimulated androstenedione in vitro. Stimulators of PKC, 1-oleoyl-2-acetyl-sn-glycerol (OAG, 50 and 100 microM) and phorbol-12-myristate-13-acetate (PMA, 50 nM), caused TIC clustering by 6 days in vitro. Clustering induced by these compounds resembled that induced by TNF. The protein kinase inhibitor, staurosporine at 1 and 10 nM, impaired TNF-induced TIC clustering for 6 days, as did the protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperizine dihydrochloride (H-7); conversely, the protein kinase inhibitor, chelerythrine chloride (0.1, 1.0 or 10 microM), did not attenuate TNF-directed clustering. The protein kinase inhibitors did not reverse the suppression of LH-stimulated androstenedione by TNF. Inhibitors of the EGF receptor PTK, A23 (10, 50, or 100 microM) and A46 (0.1, 1.0, 10, or 50 microM), impaired TNF-induced TIC clustering, while TNF suppression of LH-directed androstenedione was unaffected. EGF-induced TIC clustering was also impaired by A46, while A23 was less effective. Both A23 and A46 blocked EGF attenuation of LH-directed androstenedione after 4 days. When challenged with TNF (1 ng/ml) or PMA (50 nM), PKC activity increased in TIC. A23 (50 microM) and A46 (10 microM) each alone blocked the TNF-associated increase in PKC activity; however, PKC activity attributable to PMA was unaffected by A46. Together, these results suggest that TNF-induced TIC clustering involves activation of PTK which directs subsequent increases in PKC activity; however, mechanisms by which TNF inhibits LH-stimulated steroidogenesis remains elusive.
 ...
PMID:Involvement of protein kinase C and protein tyrosine kinase pathways in tumor necrosis factor-alpha-induced clustering of ovarian theca-interstitial cells. 814 4

Bacterial LPS induce production of cytokines such as IL-1, IL-6, and TNF in mononuclear phagocytes, and this represents a central component in the pathogenesis of septic shock syndrome. However, the mechanisms by which LPS activates these cells to express cytokines are not completely characterized. The present study addressed the role of different protein kinases in the LPS induction of cytokines. It is shown that LPS induced a 12- to 16-fold increase in IL-1 beta, IL-6, and TNF-alpha mRNA levels, and this was completely or more than 80% blocked by the protein tyrosine kinase specific inhibitors herbimycin A and genistein at the concentrations of 1.7 and 37 microM, respectively. Protein kinase C inhibition by staurosporine reduced LPS induction of TNF-alpha, whereas it had no effects on IL-6 and IL-1 beta. Inhibition of protein kinase A by H89 reduced IL-6 mRNA levels but did not detectably change IL-1 beta or TNF-alpha mRNA levels. In contrast, LPS did not increase leukemia inhibitory factor mRNA, which was constitutively expressed and not significantly reduced by these inhibitors. In addition to cytokine mRNA levels, LPS-induced IL-6 protein synthesis and IL-6 bioactivity were also reduced to baseline levels by the PTK inhibitors herbimycin A and genistein. Both PTK inhibitors also reduced the LPS activation of nuclear factor-kappa B (NF-kappa B), which is a transcription factor involved in the expression of cytokine genes such as IL-6 and TNF-alpha. The activation of NF-kappa B was also reduced by H89, whereas staurosporine had no effect on this response. In summary, these findings suggest that protein kinase C and protein kinase A appear to have selective effects in the LPS induction of cytokines, whereas PTK is required for LPS induction of a broad spectrum of cytokines and NF-kappa B activation in monocytes.
 ...
PMID:Protein tyrosine kinase activation is required for lipopolysaccharide induction of cytokines in human blood monocytes. 825 85

Preincubation of peripheral blood lymphocytes (PBL) from drug-free, healthy volunteers with either the protein tyrosine kinase inhibitor genistein (GNT, n = 10, final concentration 200 microM) or the protein kinase A activator dybutiryl-cyclic-AMP (cAMP, n = 11, final concentration 10 microM), resulted in a significant inhibition of natural killer cell activity (NKCA, expressed as percentage of specific chromium release). With the exception of 4 out of the 11 cAMP-treated samples, individual values for NKCA in the drug preincubated specimens were at least 20% below the same subject baseline activity; furthermore, NKC lytic function was non-detectable in 4 out of the 10 and in 1 out of the 11 samples pretreated with either GNT or cAMP, respectively. PBL preincubation with glutaraldehyde-fixed Gram-negative bacteria (GNB, n = 13, final GNB-to-effector cell ratio of 50 : 1) resulted in a statistically significant increase in NKCA (baseline (x +/- SD) of 21.6 +/- 16.4 and bacteria treated samples of 41.5 +/- 24.6, respectively, Student's paired t-test p < 0.05). At least a 20% increase in NKC lytic function over its own baseline value was recorded for 11 out of the 13 samples tested (Table 1). Preincubation with GNB and GNT (5 samples) not only blocked the immunostimulant effects of GNB (Student's paired t-test p < 0.05), but in most cases individual values for NKCA were similar to those recorded for GNT-only treated samples. Use of cAMP instead of GNT also blocked, but to a smaller extent, the GNB-produced increases in NKC lytic function (paired Student's t-test < 0.05). PBL preincubation with lipopolysaccharide (LPS, n = 11, final concentration 50 micrograms/ml) resulted in a statistically significant increase in NKCA (baseline (x +/- SD) of 20.7 +/- 14.1 and LPS treated samples of 39.2 +/- 18.5, respectively, Student's paired t-test < 0.05). At least a 20% increase in NKCA over its own baseline value was observed for each and everyone of the 11 samples studied (Table 2). Addition of LPS and GNT to the incubation mixture resulted not only in inhibition of the NKCA upmodulating LPS effects (Student's paired t-test p < 0.05), but each and everyone of the individual samples' NKCA were, in fact, significantly lower than their corresponding control baseline values and similar to those recorded for GNT-only treated samples. However, the use of LPS and cAMP (Table 2) produced less dramatic results, significant inhibition of LPS effect were recorded in only 2 samples (Nos 8 and 10), and individual NKCA in the remaining 3 specimens was significantly higher than the corresponding baseline value. Whereas experimental results obtained with GNT support the involvement of PTK-dependent pathways in the stimulation of human NKCA produced by GNB and LPS, cAMP experiments suggest modulation of PKA-dependent pathways as responsible for the decrease in NK lytic function produced by a number of chemicals involved in the pathophysiology associated with certain forms of stress, including septic shock. Further research in this area could help in the rational design of pharmacological approaches for the treatment of these conditions.
 ...
PMID:Activation of protein tyrosine kinase: a possible requirement for fixed-bacteria and lipopolysaccharide-induced increase in human natural killer cell activity. 873 58

Stimulation of apoptosis induced by 1-(beta-D-arabinofuranosyl)cytosine (AraC) with protein kinase inhibitors (i.e. staurosporine, CGP 41251-a protein kinase C (PKC)-selective staurosporine derivative and protein tyrosine kinase (PKT) inhibitor genistein) was examined in two human multidrug-resistant promyelocytic leukemia (HL-60) cell lines with different cell membrane drug resistance-associated glycoproteins (i.e. HL-60/VCR:MDR1 gene coded Pgp/p170 and HL-60/ADR: MRP gene coded non-Pgp/p190). Staurosporine stimulated AraC-induced apoptosis in the parental drug-sensitive HL-60 cells and both examined multidrug resistant HL-60 sublines. The stimulation of AraC-induced apoptosis by PKC selective inhibitor CGP 412251 and PTK-inhibitor genistein was approximately equal to that of staurosporine in HL-60/ADR cell line. In both parental drug sensitive HL-60 cells and Pgp/p170 positive (MDR1) HL-60/VCR, staurosporine-stimulated AraC-induced apoptosis was higher than that stimulated by the PKC selective CGP 41251 inhibitor, or PTK-inhibitor genistein. These data suggest that the molecular pathway(s) for AraC-induced apoptosis can be activated and stimulated by PKC- and PTK-inhibitors in both examined drug-resistant HL-60 cell lines. Furthermore, these data suggest that although both PKC- and PTK-dependent mechanisms are involved in AraC-induced apoptosis, in the drug-sensitive HL-60 cells and multidrug-resistant HL-60/VCR (Pgp/p170) cells this process is mediated at least partially, also by PKC- and PTK-independent mechanisms, activated by staurosporine.
 ...
PMID:Stimulation of 1-(beta-D-arabinofuranosyl)cytosine (AraC)-induced apoptosis in the multidrug resistant human promyelocytic leukemia cell lines with protein kinase inhibitors. 899 46

In rat liver epithelial cells (GN4), angiotensin II (Ang II) and thapsigargin stimulate a novel calcium-dependent tyrosine kinase (CADTK) also known as PYK2, CAKbeta, or RAFTK. Activation of CADTK by a thapsigargin-dependent increase in intracellular calcium failed to stimulate the extracellular signal-regulated protein kinase pathway but was well correlated with a 30-50-fold activation of c-Jun N-terminal kinase (JNK). In contrast, Ang II, which increased both protein kinase C (PKC) activity and intracellular calcium, stimulated extracellular signal-regulated protein kinase but produced a smaller, less sustained, JNK activation than thapsigargin. 12-O-Tetradecanoylphorbol 13-acetate (TPA), which slowly activated CADTK, did not stimulate JNK. These findings suggest either that CADTK is not involved in JNK activation or PKC activation inhibits the CADTK to JNK pathway. A 1-min TPA pretreatment of GN4 cells inhibited thapsigargin-dependent JNK activation by 80-90%. In contrast, TPA did not inhibit the >50-fold JNK activation effected by anisomycin or UV. The consequence of PKC-dependent JNK inhibition was reflected in c-Jun and c-Fos mRNA induction following treatment with thapsigargin and Ang II. Thapsigargin, which only minimally induced c-Fos, produced a much greater and more prolonged c-Jun response than Ang II. Elevation of another intracellular second messenger, cAMP, for 5-15 min also inhibited calcium-dependent JNK activation by approximately 80-90% but likewise had no effect on the stress-dependent JNK pathway. In summary, two pathways stimulate JNK in cells expressing CADTK, a calcium-dependent pathway modifiable by PKC and cAMP-dependent protein kinase and a stress-activated pathway independent of CADTK, PKC, and cAMP-dependent protein kinase; the inhibition by PKC can ultimately alter gene expression initiated by a calcium signal.
 ...
PMID:Protein kinase C and protein kinase A inhibit calcium-dependent but not stress-dependent c-Jun N-terminal kinase activation in rat liver epithelial cells. 916 74

One of the most promising targets for the rational design of anti-cancer drugs is the family of the EGF-receptor protein tyrosine kinases. Despite the high sequence homology within the ATP-binding region of protein tyrosine and/or serine threonine kinases, ATP-competitive compounds have the potential to be selective inhibitors of protein kinases. Dianilino-phthalimides CGP 52 411 and CGP 53,353 have been identified as potent and ATP-competitive inhibitors of the EGF-R tyrosine kinase with no or only minor activity against a panel of tyrosine and serine/threonine kinases. Using a calculated 3-D computer model of the catalytic domain of the EGF-R-tyrosine kinase together with CGP 52 411 as example of an ATP-competitive inhibitor, a pharmacophore model for ATP-competitive inhibitors in the active site of the EGF-R PTK was developed. With the help of this model, 4-phenylamino-7H-pyrrolo[2,3-d]pyrimidines were then identified as new potent EGF-R PTK inhibitors. In an interactive process, the class of the 4-phenylamino-pyrrolo-pyrimidines was optimized and structure-activity-relationship of a series of derivatives thereof are discussed. In vitro, the most active compounds (CGP 59 326, CGP 60 261, CGP 62 706) inhibited the EGF-R tyrosine kinase with IC50 value between 6-30 nM. High selectivity towards a panel of non-receptor tyrosine kinases (c-SRC, v-Abl) and serine/threonine kinases (PKC alpha, PKA) was observed. Kinetic analysis revealed competitive type kinetics relative to ATP. In cells, EGF-stimulated cellular tyrosine phosphorylation was inhibited by these compounds at IC50 values between 0.1-0.3 microM, whereas the ligand-induced receptor autophosphorylation of the PDGR-R was not effected by concentrations up to 100 microM. Furthermore, CGP 59 326, CGP 60 261, CGP 62 706 were able to selectively inhibit c-fos mRNA expression in EGF-dependent cell lines with (IC50) approx. 0.1-1 microM) but not in EGF-independent cell systems (IC50 > 100 microM). Proliferation of the EGF-dependent MK cell line was inhibited with similar IC50 values. In addition, CGP 59 326 and CGP 62 706 showed good in vivo efficacy at low doses after oral or subcutaneous administration in nude mice tumor models using xenografts of the EGF-dependent A431 cell lines. The ED50 values were between 1.5-2 mg/kg. Phenylamino-pyrrolo-pyrimidines therefore represent a new series of tyrosine kinase inhibitors which preferentially inhibit the EGF-mediated signal transduction pathway and have the characteristics for further evaluation as anticancer agents.
 ...
PMID:Design and synthesis of novel tyrosine kinase inhibitors using a pharmacophore model of the ATP-binding site of the EGF-R. 919 32


1 2 3 4 Next >>