Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.11.17 (CaMKII)
 4,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the effect of staurosporine on Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) purified from rat brain. (a) Staurosporine (10-100 nM) inhibited the activity of CaM kinase II. The half-maximal and maximal inhibitory concentrations were 20 and 100 nM, respectively. (b) The inhibition with staurosporine was of the noncompetitive type with respect to ATP, calmodulin, and phosphate acceptor (beta-casein). (c) Staurosporine suppressed the auto-phosphorylation of alpha- and beta-subunits of CaM kinase II at concentrations similar to those at which the enzyme activity was inhibited. (d) Staurosporine also attenuated the Ca2+/calmodulin-independent activity of the autophosphorylated CaM kinase II. These results suggest that staurosporine inhibits CaM kinase II by interacting with the catalytic domain, distinct from the ATP-binding site or substrate-binding site, of the enzyme and that staurosporine is an effective inhibitor for CaM kinase II in the cell system.
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PMID:Staurosporine: an effective inhibitor for Ca2+/calmodulin-dependent protein kinase II. 184 74

We examined whether protein kinase C activation plays a modulatory or an obligatory role in exocytosis of catecholamines from chromaffin cells by using PKC(19-31) (a protein kinase C pseudosubstrate inhibitory peptide), Ca/CaM kinase II(291-317) (a calmodulin-binding peptide), and staurosporine. In permeabilized cells, PKC (19-31) inhibited the phorbol ester-mediated enhancement of Ca2(+)-dependent secretion as much as 90% but had no effect on Ca2(+)-dependent secretion in the absence of phorbol ester. The inhibition of the phorbol ester-induced enhancement of secretion by PKC (19-31) was correlated closely with the ability of the peptide to inhibit in situ phorbol ester-stimulated protein kinase C activity. PKC(19-31) also blocked 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced phosphorylation of numerous endogenous proteins in permeabilized cells but had no effect on Ca2(+)-stimulated phosphorylation of tyrosine hydroxylase. Ca/CaM kinase II(291-317), derived from the calmodulin binding region of Ca/calmodulin kinase II, had no effect on Ca2(+)-dependent secretion in the presence or absence of phorbol ester. The peptide completely blocked the Ca2(+)-dependent increase in tyrosine hydroxylase phosphorylation but had no effect on TPA-induced phosphorylation of endogenous proteins in permeabilized cells. To determine whether a long-lived protein kinase C substrate might be required for secretion, the lipophilic protein kinase inhibitor, staurosporine, was added to intact cells for 30 min before permeabilizing and measuring secretion. Staurosporine strongly inhibited the phorbol ester-mediated enhancement of Ca2(+)-dependent secretion. It caused a small inhibition of Ca2(+)-dependent secretion in the absence of phorbol ester which could not be readily attributed to inhibition of protein kinase C. Staurosporine also inhibited the phorbol ester-mediated enhancement of elevated K(+)-induced secretion from intact cells while it enhanced 45Ca2+ uptake. Staurosporine inhibited to a small extent secretion stimulated by elevated K+ in the absence of TPA. The data indicate that activation of protein kinase C is modulatory but not obligatory in the exocytotoxic pathway.
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PMID:Activation of protein kinase C is not required for exocytosis from bovine adrenal chromaffin cells. The effects of protein kinase C(19-31), Ca/CaM kinase II(291-317), and staurosporine. 217 38

The effect of protein kinase C activators and inhibitors on histamine-stimulated phospholipase C in bovine adrenal medullary cells has been investigated. The protein kinase C activators, phorbol 12,13-dibutyrate (PDB) or sn-1,2-dioctanoylglycerol (DOG), inhibited histamine-stimulation of phospholipase C. This inhibition was prevented by the protein kinase C-selective inhibitor Ro 31-8220 (3-[1-[3-(2-isothioureido) propyl]indol-3-yl]-4-(1-methylindol-3-yl)-3-pyrrolin-2,5-dio ne) but not the broad spectrum protein kinase inhibitor staurosporine. Indeed staurosporine on its own inhibited both the histamine-stimulated response and, in permeabilized cells, phospholipase C activated by Ca2+. Staurosporine inhibition of phospholipase C is unlikely to be mediated via protein kinase A or Ca2+/calmodulin-dependent protein kinase because it was not reproduced by selective inhibition of these kinases. Staurosporine treatment, however, reduced inositol phospholipid levels in stimulated cells. Thus staurosporine and Ro 31-8220, two widely used protein kinase C inhibitors, have quite different effects on phospholipase C activation. Furthermore, staurosporine may cause this inhibition through a reduction in the level of phospholipase C substrate.
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PMID:Staurosporine inhibits inositol phosphate formation in bovine adrenal medullary cells. 758 17

Effects of Ca2+ on [3H]5-hydroxytryptamine (5-HT) uptake into rat cortical synaptosomes were studied. The uptake was enhanced in the presence of Ca2+ in Krebs-Ringer medium and the uptake at 0.3-5 mM Ca2+ was 2.4-2.7 times greater than that observed in the absence of Ca2+. The maximal increase at the concentration of 1 mM Ca2+ was achieved after 2 min preincubation. Ca(2+)-dependent enhancement of the [3H]5-HT uptake reflected an increase in Vmax of the uptake process. However, Kd and Bmax values for [3H]paroxetine were not significantly changed in the presence of 1 mM Ca2+ compared with Ca(2+)-free condition. On the other hand, uptake was still enhanced after synaptosomes were washed with Ca(2+)-free after preincubation with 1 mM Ca2+. Staurosporine (a protein kinase C inhibitor) and wortmannin (a myosin light chain kinase inhibitor) did not affect Ca(2+)-dependent enhancement of the uptake, whereas 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4-phenylpiperazin e (KN-62, an inhibitor of Ca2+ /calmodulin-dependent kinase II) and N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7, a calmodulin antagonist) significantly reduced it. Moreover, L-type, but not P- or N-type, voltage-dependent Ca(2+)-channel blockers suppressed enhancement of the uptake. These results indicate that Ca(2+)-dependent enhancement of [3H]5-HT uptake is mediated by activation of calmodulin-dependent protein kinases, suggesting a possibility of calmodulin-dependent regulation of in vivo 5-HT uptake.
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PMID:Possible involvement of calmodulin-dependent kinases in Ca(2+)-dependent enhancement of [3H]5-hydroxytryptamine uptake in rat cortex. 894 31

The cholinergic agonist carbachol stimulates the apical H+-K+-ATPase and apical as well as basolateral K+ channels in the rat distal colon. The effect of carbachol was tested in the presence of different inhibitors of the Ca2+ signaling pathway in order to characterize the intracellular mechanisms involved. Both carbachol-stimulated Rb+-efflux as well as carbachol-stimulated mucosal Rb+-uptake were dependent on the presence of serosal Ca2+. The Ca2+-calmodulin antagonist calmidazolium (10(-7) mol l(-1)) inhibited the stimulation of mucosal and serosal Rb+ efflux by carbachol. A similar effect had KN-62 (10(-5) mol l(-1)), an inhibitor of the Ca2+-calmodulin-dependent kinase II, suggesting the regulation of basolateral and apical K+ channels by this kinase. Staurosporine (10(-6) mol l(-1)), which potently inhibits protein kinase C, did not alter the effect of carbachol on Rb+ efflux, although the stimulation of apical Rb+ efflux by carbachol seemed to be less prolonged, indicating that protein kinase C is not involved in the regulation of K+ permeability. In contrast, mucosal Rb+ uptake, which is determined by the ouabain- and vanadate-sensitive K+ transport via the apical H+-K+-ATPase, was decreased to nearly one third of control values in the presence of calmidazolium. Both calmidazolium and staurosporine, but not KN-62, prevented the stimulatory action of carbachol on the H+-K+-ATPase, suggesting a synergistic control of this ion pump by both Ca2+-calmodulin and protein kinase C.
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PMID:Involvement of calmodulin and protein kinase C in the regulation of K+ transport by carbachol across the rat distal colon. 1044 29

Because the activity of the sodium pump (Na-K-ATPase) influences the secretion of aldosterone, we determined how extracellular potassium (K(o)) and calcium affect sodium pump activity in rat adrenal glomerulosa cells. Sodium pump activity was measured as ouabain-sensitive (86)Rb uptake in freshly dispersed cells containing 20 mM sodium as measured with sodium-binding benzofluran isophthalate. Increasing K(o) from 4 to 10 mM in the presence of 1.8 mM extracellular calcium (Ca(o)) stimulated sodium pump activity up to 165% and increased intracellular free calcium as measured with fura 2. Increasing K(o) from 4 to 10 mM in the absence of Ca(o) stimulated the sodium pump approximately 30% and did not increase intracellular free calcium concentration ([Ca(2+)](i)). In some experiments, addition of 1.8 mM Ca(o) in the presence of 4 mM K(o) increased [Ca(2+)](i) above the levels observed in the absence of Ca(o) and stimulated the sodium pump up to 100%. Ca-dependent stimulation of the sodium pump by K(o) and Ca(o) was inhibited by isradipine (10 microM), a blocker of L- and T-type calcium channels, by compound 48/80 (40 microg/ml) and calmidizolium (10 microM), which inhibits calmodulin (CaM), and by KN-62 (10 microM), which blocks some forms of Ca/CaM kinase II (CaMKII). Staurosporine (1 microM), which effectively blocks most forms of protein kinase C, had no effect. In the presence of A-23187, a calcium ionophore, the addition of 0.1 mM Ca(o) increased [Ca(2+)](i) to the level observed in the presence of 10 mM K(o) and 1.8 mM Ca(o) and stimulated the sodium pump 100%. Ca-dependent stimulation by A-23187 and 0.1 mM Ca(o) was not reduced by isradipine but was blocked by KN-62. Thus, under the conditions that K(o) stimulates aldosterone secretion, it stimulates the sodium pump by two mechanisms: direct binding to the pump and by increasing calcium influx, which is dependent on Ca(o). The resulting increase in [Ca(2+)](i) may stimulate the sodium pump by activating CaM and/or CaMKII.
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PMID:Effects of extracellular calcium and potassium on the sodium pump of rat adrenal glomerulosa cells. 1112 83

A two-micropipette current-clamp technique was used to record electrophysiological responses from the somatic muscle of Ascaris suum. Levamisole and acetylcholine were applied to the bag region of the muscle using a microperfusion system. Depolarizations produced by 10 s applications of 10 micro mol l(-1) levamisole or 20 s applications of 10 micro mol l(-1) acetylcholine were recorded. The effect on the peak membrane potential change of the kinase antagonists H-7, staurosporine, KN-93 and genistein was observed. H-7 (30 micro mol l(-1)), a non-selective antagonist of protein kinases A, C and G but which has little effect on Ca(2+)/calmodulin-dependent kinase II (CaM kinase II), did not produce a significant effect on the peak response to levamisole or acetylcholine. Staurosporine (1 micro mol l(-1)), a non-selective kinase antagonist that has effects on protein kinases A, C and G, CaM kinase and tyrosine kinase, reduced the mean peak membrane potential response to levamisole from 6.8 mV to 3.9 mV (P<0.0001) and the mean response to acetylcholine from 5.5 mV to 2.8 mV (P=0.0016). The difference between the effects of H-7 and staurosporine suggested the involvement of CaM kinase II and/or tyrosine kinase. KN-93, a selective CaM kinase II antagonist, reduced the mean peak response to levamisole from 6.2 mV to 2.7 mV (P=0.035) and the mean peak response of acetylcholine from 4.7 mV to 2.0 mV (P=0.0004). The effects indicated the involvement of CaM kinase II in the phosphorylation of levamisole and acetylcholine receptors. The effect of extracellular Ca(2+) on the response to levamisole was assessed by comparing responses to levamisole in normal and in low-Ca(2+) bathing solutions. The response to levamisole was greater in the presence of Ca(2+), an effect that may be explained by stimulation of CaM kinase II. Genistein (90 micro mol l(-1)), a selective tyrosine kinase antagonist, reduced peak membrane potential responses to levamisole from a mean of 6.4 mV to 3.3 mV (P=0.001). This effect indicated the involvement of tyrosine kinase in maintaining the receptor.
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PMID:Levamisole receptor phosphorylation: effects of kinase antagonists on membrane potential responses in Ascaris suum suggest that CaM kinase and tyrosine kinase regulate sensitivity to levamisole. 1243 19

Praziquantel (PZQ) is the drug of choice for schistosomiasis. The potential drug resistance necessitates the search for adjunct or alternative therapies to PZQ. Previous functional genomics has shown that RNAi inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) gene in Schistosoma adult worms significantly improved the effectiveness of PZQ. Here we tested the in vitro efficacy of 15 selective and non-selective CaMK inhibitors against Schistosoma mansoni and showed that PZQ efficacy was improved against refractory juvenile parasites when combined with these CaMK inhibitors. By measuring CaMK activity and the mobility of adult S. mansoni, we identified two non-selective CaMK inhibitors, Staurosporine (STSP) and 1Naphthyl PP1 (1NAPP1), as promising candidates for further study. The impact of STSP and 1NAPP1 was investigated in mice infected with S. mansoni in the presence or absence of a sub-lethal dose of PZQ against 2- and 7-day-old schistosomula and adults. Treatment with STSP/PZQ induced a significant (47-68%) liver egg burden reduction compared with mice treated with PZQ alone. The findings indicate that the combination of STSP and PZQ dosages significantly improved anti-schistosomal activity compared to PZQ alone, demonstrating the potential of selective and non-selective CaMK/kinase inhibitors as a combination therapy with PZQ in treating schistosomiasis.
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PMID:Use of kinase inhibitors against schistosomes to improve and broaden praziquantel efficacy. 3274 2