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

The ability of a papaverine-derived bronchodilator, AH 21-132, to inhibit cyclic nucleotide hydrolysis and to increase the cAMP content and the activity of cAMP-dependent protein kinase (A-kinase) was evaluated in bovine tracheal smooth muscle (BTSM) and related to the mechanical effects elicited by this compound in vitro. AH 21-132 (100 nM-1 mM) produced a concentration-related relaxation of BTSM pre-contracted with methacholine (MCh) that was subject to marked functional antagonism. AH 21-132 (100 microM) also displayed anti-spasmogenic activity preventing the generation of tone induced by low, but not high, concentrations of MCh. Neither the spasmolytic nor anti-spasmogenic effects of AH 21-132 were antagonized by the beta 2-adrenoceptor blocking drug ICI 118551 (50 nM). Three Ca(2+)- and calmodulin-independent cyclic nucleotide phosphodiesterases (PDE) were resolved from the soluble fraction of BTSM homogenates by Q-Sepharose anion exchange chromatography. These PDEs were identified by kinetic and inhibitor sensitivity criteria as the Type II (cGMP-stimulated), Type IV (Ro 20-1724-inhibited) and Type V (cGMP-specific) isoenzymes. A small amount (approximately 5%) of a Type III PDE seemed to be present but this was not identified with certainty. AH 21-132 selectively inhibited Type IV PDE in a competitive manner with an IC50 and KI of 3.7 and 2.7 microM, respectively. AH 21-132 similarly increased the cAMP content (from 5.3 to 23.1 pmol/mg protein after 1 mM AH 21-132) and activated A-kinase (from 29.6% to 53.5% after 1 mM AH 21-132) in intact BTSM over the same concentration range at which this compound influenced tone. In addition, AH 21-132 in high concentrations (greater than 100 microM), while exerting no direct effect on A-kinase itself, markedly potentiated (ca. four-fold at 3 mM AH 21-132) the ability of cAMP to activate A-kinase without affecting the affinity of cAMP for this enzyme. It is concluded that the spasmolytic and anti-spasmogenic effects of AH 21-132 in BTSM may be related, in part, to its ability to inhibit Type IV PDE, increase the intracellular cAMP content and so activate A-kinase. A cyclic nucleotide-dependent mechanism is therefore proposed. In addition, the ability of AH 21-132 to augment cAMP-dependent phosphorylation in a cell-free system, when Type IV PDE is inhibited fully, provides the possibility that the observed relaxation elicited by high concentrations of AH 21-132, while cAMP-dependent, does not require any further increase in the intracellular cAMP concentration.
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PMID:Selective inhibition of a high affinity type IV cyclic AMP phosphodiesterase in bovine trachealis by AH 21-132. Relevance to the spasmolytic and anti-spasmogenic actions of AH 21-132 in the intact tissue. 165 Feb 18

Using the sequence homology approach for cloning related genes within the G-protein-coupled receptor gene family, we have cloned the gene for the rat beta 1-adrenergic receptor (beta 1-AR). The rat beta 1-adrenergic receptor gene was isolated from a lambda EMBL3 rat genomic DNA library using the hamster beta 2-adrenergic receptor (beta 2-AR) coding sequence as a probe under low stringency hybridization conditions. The rat beta 1-AR gene encodes a protein of 466 amino acids that contains one consensus site for N-linked glycosylation (Asn-15) and three consensus sites for cAMP-dependent protein kinase phosphorylation (Ser-296, Ser-301, and Ser-401). The encoded rat beta 1-AR is 98 and 91% similar at the amino acid level with the human beta 1-AR in the transmembrane domains and in the overall sequence, respectively. Genomic Southern blot and gene dosage analyses indicate that the rat beta 1-AR gene is a single copy gene. The tissue distribution of the rat beta 1-AR mRNA was highest in the pineal gland with other brain regions and peripheral tissues, including the heart, expressing the mRNA at moderate levels. The bacteriophage clone containing the rat beta 1-AR gene with its natural promoter was co-transfected with the selectable marker (pRSVneo) conferring neomycin resistance into beta 1-AR-deficient mouse L cells. Analyses of the selected transfectant demonstrates efficient expression of the beta 1-AR gene and functional receptor. 125I-Labeled iodocyanopindolol bound transfectant membranes with an affinity of KD = 24 pm; the beta 1-AR-selective antagonist ICI 89,406 displaced iodocyanopindolol binding with a Ki approximately 140 times lower than that for the beta 2-AR-selective antagonist ICI 118,551. In addition, in the transfectant cell line, adenylylcyclase was stimulated by beta-adrenergic receptor agonists with the rank order of potency of isoproterenol greater than norepinephrine = epinephrine, consistent with properties expected of the beta 1-AR subtype.
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PMID:Molecular cloning and expression of the rat beta 1-adrenergic receptor gene. 169 99

Primary uterine cell cultures were used to study multifactor regulation of progesterone receptor (PR) and the signal transduction pathways which may serve to mediate that regulation. Increases in intracellular cAMP, brought about by treatment with cholera toxin plus isobutyl methyl xanthine or by addition of 8-bromo-cAMP, result in 6- to 7-fold increases in the intracellular content of PR as monitored by [3H]R5020 binding and by Western immunoblot using anti-PR antibodies. In these primary cultures of uterine cells isolated from 19-day-old immature rats, 8-bromo-cAMP evokes significant increases in PR by 8 h with maximal increases by 24 h. This time course and magnitude of PR stimulation are similar to those evoked by maximally effective concentrations of estradiol (3 x 10(-9) M) or IGF-I (20 ng/ml). Dose-response studies reveal that 10(-6) to 10(-4) M concentrations of 8-bromo-cAMP (8-Br-cAMP) elicit a maximal response. In contrast, 8-bromo-cGMP over a wide concentration range was unable to elevate cellular PR levels. Under these culture conditions, cell proliferation was not altered by treatment with any of these agents. Although estrogen, cAMP, and insulin-like growth factor I (IGF-I) may act via different pathways to increase PR, the effects evoked by maximally effective concentrations of these agents are not additive implying involvement of a common component. The increases in PR evoked by estradiol, cAMP, or IGF-I are markedly suppressed by treatment with antiestrogen (ICI 164,384) or the cyclic nucleotide-dependent protein kinase inhibitor H8 or the protein kinase A inhibitor PKI, indicating the involvement of the estrogen receptor and phosphorylation pathways in PR regulation by these three agents. The present studies identify cAMP, as well as estrogen and IGF-I, as important regulators of the level of PR in uterine cells and suggest that multiple factors, including those affecting intracellular cAMP levels, might influence responsiveness to progestins via regulation of the intracellular PR content.
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PMID:Progesterone receptor regulation in uterine cells: stimulation by estrogen, cyclic adenosine 3',5'-monophosphate, and insulin-like growth factor I and suppression by antiestrogens and protein kinase inhibitors. 170 63

Expression of tissue plasminogen activator (tPA) gene is stimulated by gonadotropins in granulosa cells. Because adrenergic agents interact with specific granulosa cell receptors to increase progesterone biosynthesis, the effects of these pounds on tPA activity and mRNA levels were also investigated. Cells obtained from immature estrogen-treated rats were initially cultured with FSH or medium alone for 2 days. They were then reincubated with various adrenergic agents before measurement of medium tPA activity using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by a fibrin overlay technique. In addition, cellular RNA was extracted, and tPA mRNA levels were analyzed using a specific rat cRNA probe. Isoproterenol, a beta-adrenergic agonist, stimulated the secretion of tPA activity in a dose-dependent manner, with FSH-pretreated cells secreting higher levels of the enzyme than cells without FSH priming. Northern blot hybridization of total RNA showed the accumulation of a 22S species tPA message in cells treated with isoproterenol, suggesting increased expression of the tPA gene. Furthermore, slot blot hybridization of RNA from these cells indicated a time-dependent increase in tPA mRNA, with maximal induction between 1-3 h of incubation. A selective beta 2-adrenergic agonist, terbutaline, but not the beta 1-agonist dobutamine, stimulated tPA activity. Also, the stimulatory effect of isoproterenol was blocked by a beta 2-antagonist (ICI-118,551) but not by a beta 1-antagonist (practolol), suggesting the involvement of a beta 2-receptor. Like FSH and LH, isoproterenol increased extra- and intracellular cAMP levels. Cotreatment of a saturating dose of isoproterenol with FSH or LH did not further stimulate tPA activity. Similar to that in cells treated with FSH, inhibition of protein synthesis by cycloheximide resulted in the superinduction of tPA mRNA in isoproterenol-treated cells. Thus, activation of beta 2-adrenergic receptors in granulosa cells induces tPA mRNA and activity, presumably through the protein kinase-A pathway shared by gonadotropins. Adrenergic neurotransmitters may be potential intraovarian regulators of this important protease.
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PMID:Beta-adrenergic agents stimulate tissue plasminogen activator activity and messenger ribonucleic acid levels in cultured rat granulosa cells. 247 32

This study examined the effects of selective activation of kappa 1-opioid receptors on excitatory transmission in substantia gelatinosa (SG) using intracellular recordings from SG neurons in transverse slices of the young rat lumbar spinal cord. Monosynaptic and polysynaptic excitatory postsynaptic potentials (EPSPs) were evoked by orthodromic electrical stimulation of A delta or C primary afferent fibers in the dorsal root after blocking inhibitory inputs with bicuculline and strychnine, NMDA receptors with D-2-amino-5-phosphonovaleric acid and mu- and delta-opioid receptors with CTAP and ICI 174,864, respectively. Bath application of dynorphin A1-17 or U-69, 593 caused dual modulation of the peak amplitude of presumed monosynaptic AMPA receptor-mediated EPSPs, decreasing synaptic potentials at nanomolar concentrations in a majority of SG cells examined (dynorphin, 63%; U-69,593, 91%), and increasing EPSPs at micromolar concentrations. Only the inhibitory action of dynorphin A1-17 was consistently and completely blocked by norbinaltorphimine (nor-BNI). Since U-69,593 and nor-BNI are selective for the kappa 1-opioid receptors, the depression of EPSPs is likely to be mediated by the kappa1-opioid receptors. Under conditions of blockade of synaptic transmission with TTX and mu-and delta-opioid receptors, dynorphin A1-17 and U-69,593 hyperpolarize most of SG neurons and decrease their membrane input resistance, the finding suggesting that direct interaction of kappa-agonists with a postsynaptic receptor is likely explanation for the inhibition of EPSPs. However, in some SG cells, the inhibition of EPSPs appears to be of presynaptic origin since dynorphin A1-17 and U-69,593 did depress the EPSPs in the absence of changes in passive membrane properties. Rp-cAMPS, a membrane permeant potent competitive inhibitor of cAMP-activated protein kinase, prevented the depressant effect of dynorphin A 1-17. This finding suggested a possibility that dynorphin A1-17, acting through a decrease in intracellular cyclic AMP levels, can reduce the synaptic responses of SG neurons. These results provide the first electrophysiological demonstration that the activation of kappa 1-opioid receptors inhibits AMPA receptor-mediated primary afferent neurotransmission in the substantia gelatinosa of the young rat spinal cord. This effect may mediate the ability of kappa-receptor agonists to produce antinociception.
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PMID:kappa-opioid receptor agonists modulate excitatory transmission in substantia gelatinosa neurons of the rat spinal cord. 747 39

1. Adenosine is known to stimulate capillary outgrowth and endothelial cell proliferation, but the underlying mechanism has not been identified. In order to identify the receptor subtype involved, the effects of adenosine receptor agonists and antagonists on human umbilical vein endothelial cell (HUVEC) proliferation were investigated. 2. Raising intracellular adenosine levels by use of the adenosine transport inhibitor, 4-nitrobenzylthioinosine (NBMPR) did not affect cell growth. This observation suggests that stimulation of an extracellular adenosine receptor generates the mitogenic signal. 3. In the presence of adenosine deaminase (ADA), which was used to remove adenosine present in the culture medium, the adenosine receptor agonists N-ethylcarboxamidoadenosine (NECA, non-selective) and CGS21680 (A2A-receptor-selective) stimulated [3H]-thymidine incorporation with a half-maximum effect at about 10 nM, while N6-cyclopentyladenosine (CPA, A1-selective) was about 100 fold less potent. The adenosine receptor antagonist, xanthine amine congener (XAC) produced a concentration-dependent decrease in endothelial cell proliferation with a half-maximum effect at about 10 nM. Hence, stimulation of an endothelial A2A-adenosine receptor seems responsible for the mitogenic signal. 4. In the presence of ADA, isoprenaline is also able to stimulate [3H]-thymidine incorporation with a half maximal effect of about 3 nM, an effect, which is reversed by the highly beta 2-selective antagonist, ICI 118,551. In the absence of ADA, isoprenaline exerts only a minor stimulatory effect. Combination of A2A adenosine and beta 2-adrenoceptor agonists did not further enhance [3H]-thymidine incorporation when compared to the sole addition of each agonist. We therefore conclude that both receptors stimulate endothelial cell proliferation via a common signal transduction pathway. 5. Both receptors are coupled to stimulation of adenylyl cyclase via the stimulatory G protein G8.However, direct activation of downstream effectors in the cyclic AMP-signalling cascade (G8 with cholera toxin, adenylyl cyclase with forskolin, protein kinase A with 8Br-cyclic AMP) not only failed to mimic the action of receptor-activation, but even reduced cell proliferation.6. Similarly, pertussis toxin-treatment which inactivated the Gi 2 protein present in HUVEC and thus inhibited cell proliferation per se, did not impair the ability of A2A-receptor agonists to stimulate cell proliferation. This suggests that the A2A-adenosine and beta2-adrenoceptor-mediated stimulation of endothelial cell proliferation occurs via a mechanism that is independent of G8 and Gi.
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PMID:Stimulation of human umbilical vein endothelial cell proliferation by A2-adenosine and beta 2-adrenoceptors. 759 25

The beta-adrenergic agonist isoproterenol induced an increase in intracellular calcium concentration ([Ca2+]i) in rat submandibular granular ducts that was blocked by beta-adrenergic but not by alpha-adrenergic or muscarinic antagonists. This effect was only partially inhibited by the selective beta 1- and beta 2-adrenergic antagonists atenolol and ICI-118,551, but was completely blocked by the combination of the two, suggesting the involvement of multiple (or atypical) beta-adrenergic receptor subtypes. The response to isoproterenol was mimicked by forskolin, 3-isobutyl-1-methylxanthine, and dibutyryl adenosine 3',5'-cyclic monophosphate, but it was blocked by protein kinase inhibitors. The response of [Ca2+]i to isoproterenol was sustained in Ca(2+)-replete replete medium but transient in Ca(2+)-free medium, indicating the involvement of both Ca2+ entry and release from intracellular stores. However, isoproterenol stimulation produced no increase in ductal inositol phosphate levels. In addition, isoproterenol was still able to increase [Ca2+]i after the carbachol-induced depletion of inositol 1,4,5-trisphosphate (IP3)-sensitive calcium stores. We conclude that isoproterenol, acting through cAMP, releases Ca2+ from an IP3-insensitive intracellular store in salivary granular ducts.
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PMID:Beta-adrenergic stimulation and cAMP mobilize Ca2+ from an IP3-insensitive pool in rat submandibular granular ducts. 769 95

We have previously reported that addition of 8-bromocyclic AMP enhances the stimulatory effect of dexamethasone on the expression of the angiotensinogen gene in mouse hepatoma cells in vitro. Isoproterenol is known to stimulate the synthesis of hepatic intracellular cyclic AMP via beta-adrenergic receptors. To study the possible effect of beta-adrenergic receptors on the expression of the angiotensinogen gene in mouse hepatoma cells, we transiently transfected them with a fusion gene with the 5'-flanking region of the angiotensinogen gene linked to a bacterial chloramphenicol acetyltransferase coding sequence as a reporter, pOCAT (ANG N-1498/+18). The addition of isoproterenol (10(-9) to 10(-5) mol/L) alone had no stimulatory effect on the expression of pOCAT (ANG N-1498/+18). In the presence of dexamethasone (10(-6) mol/L), however, isoproterenol enhanced the stimulatory effect on the dexamethasone on the expression of pOCAT (ANG N-1498/+18). The enhancing effect of isoproterenol was inhibited by the presence of propranolol (beta 1- and beta 2-adrenergic receptor antagonist) and ICI 118,551 (beta 2-adrenergic receptor antagonist) but not by the presence of atenolol (beta 1-adrenergic receptor antagonist). Furthermore, the addition of Rp-cAMP (an inhibitor of protein kinase A I and II) blocked the enhancing effect of isoproterenol. These studies demonstrated that isoproterenol enhances the stimulatory effect of dexamethasone on the expression of the angiotensinogen gene in mouse hepatoma cells via beta 2-adrenergic receptor and cyclic AMP-dependent protein kinase pathways. Our data may be important in understanding the molecular mechanism(s) of the stimulatory effect of catecholamines/glucocorticoid-induced expression of the angiotensinogen gene in the liver.
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PMID:Beta-adrenergic receptors and angiotensinogen gene expression in mouse hepatoma cells in vitro. 784 40

The uterine content of c-fos protein, cyclin B1 (cell cycle protein) and cdc2 p34(cyclin-dependent kinase) in immature and mature rats was determined using the enhanced chemiluminescence(ECL) western blot method. Cyclin B1 was found predominantly in immature rat uterus and cdc2 p34 only in mature rat uterus. Several isoforms of c-fos oncogene protein were present in both mature and immature rat uteri. An additional immunoreactive c-fos protein with an estimated molecular weight of 28 kDa was found in mature rat uterus and was missing in immature uterus. Uteri from ovariectomized rats treated with estrogen and/or ICI 182,780, an antiestrogen, were analyzed by ECL western blot. cdc2 p34 and the c-fos 28 kDa protein were found in estradiol-treated rat uteri and were not detected in uteri of control and ICI 182,780-treated animals; whereas Cyclin B1 was absent in uteri from control and estradiol-treated ovariectomized animals. ICI 182,780 administered to estradiol-treated ovariectomized rats blocked the induction of cdc2 p34 and the c-fos 28 kDa protein in the uterus. The present results show that the production of the cell cycle factors, cyclin B1, cdc2 p34 and c-fos, during rat uterine growth are under different regulatory controls. cdc2 p34 and c-fos 28 kDa protein are under the control of estradiol; whereas cyclin B1 and the majority of the immunoreactive isoforms of c-fos are not influenced by this hormone.
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PMID:Differential effect of estrogen on the production of cyclin B1, cdc2 p34 and c-fos protein in rat uterus. 788 99

To investigate whether the expression of the renal angiotensinogen (ANG) gene is regulated by beta-adrenoceptors and the cAMP-dependent protein kinase A pathway, we introduced stably the fusion gene containing the 5'-flanking regulatory sequence of the ANG gene with a human growth hormone (hGH) gene as a reporter, pOGH (ANG N-1498/+18), into opossum kidney (OK) cells. We successfully obtained several stable transformants with a high expression of the pOGH (ANG N-1498/+18) fusion gene. One stable transformant (OK 27) that is able to maintain the expression of pOGH (ANG N-1498/+18) in culture for more than a year was used in the present study. The level of expression of the pOGH (ANG N-1498/+18) in OK 27 was evaluated by the amount of immunoreactive-hGH (IR-hGH) secreted into the culture medium. The addition of isoproterenol (10(-11) M to 10(-9) M) stimulated the expression of pOGH (ANG N-1498/+18) and increased the accumulation of intracellular cAMP. Higher concentrations of isoproterenol (that is, greater than 10(-9) M) had low or minimal effect. In contrast, the addition of 8-bromo-cAMP (8-Br-cAMP) and forskolin stimulated the expression of pOGH (ANG N-1498/+18) in a dose-dependent manner. The stimulatory effect of isoproterenol was blocked by the presence of propranolol, atenolol and ICI 118,551. The addition of ICI 118,551, however, was less effective than atenolol. Furthermore, the stimulatory effect of isoproterenol and 8-Br-cAMP on the expression of the pOGH (ANG N-1498/+18) was inhibited by the presence of Rp-cAMP (an inhibitor of cAMP-dependent protein kinase A I and II).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Isoproterenol and 8-bromo-cyclic adenosine monophosphate stimulate the expression of the angiotensinogen gene in opossum kidney cells. 799 91


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