Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously found the neuronal cell-type specific promoter and binding partner of the beta isoform of Ca(2+)/calmodulin-dependent protein kinase II (beta CaM kinase II) in rat brain [Donai, H., Morinaga, H., Yamauchi, T., 2001. Genomic organization and neuronal cell type specific promoter activity of beta isoform of Ca(2+)/calmodulin-dependent protein kinase II of rat brain. Mol. Brain Res. 94, 35-47]. In the present study, we purified a protein that binds specifically a promoter region of beta CaM kinase II gene from a nuclear extract of the rat cerebellum using DEAE-cellulose column chromatography, ammonium sulfate fractionation, gel filtration and polyacrylamide gel electrophoresis. The purified protein was identified as rat leucine-rich protein 157 (rLRP157) using tandem mass spectrometry. Then, we prepared its cDNA by reverse transcriptase-polymerase chain reaction (RT-PCR) from poly(A)(+)RNA of rat cerebellum. The rLRP157 cDNA was introduced into mouse neuroblastomaxrat glioma hybrid NG108-15 cells, and cells stably expressing rLRP157 (NG/LRP cells) were isolated. Binding of rLRP157 with the promoter sequence was confirmed by electrophoretic mobility shift assay using nuclear extract of NG/LRP cells. A luciferase reporter gene containing a promoter of beta CaM kinase II was transiently expressed in NG/LRP cells. Under the conditions, the promoter activity was enhanced about 2.6-fold in NG/LRP cells as compared with wild-type cells. The expression of rLRP157 mRNA was paralleled with that of beta CaM kinase II in the adult and embryo rat brain detected by in situ hybridization. Nuclear localization of rLRP157 was confirmed using GFP-rLRP157 fusion protein investigated under a confocal microscope. These results indicate that rLRP157 is one of the proteins binding to, and regulating the activity of, the promoter of beta CaM kinase II.
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PMID:Rat leucine-rich protein binds and activates the promoter of the beta isoform of Ca2+/calmodulin-dependent protein kinase II gene. 1733 62

Continuous ingestion of phencyclidine (PCP) in humans produces long-lasting schizophrenic-like cognitive dysfunction. Although a malfunction of dopaminergic and/or glutamatergic neurotransmission is implicated in the etiology of schizophrenia, involvement of the dopaminergic-glutamatergic neurotransmission in the cognitive dysfunction induced by repeated PCP treatment is minor. We demonstrated that mice treated with PCP (10 mg/kg/day s.c.) for 14 days displayed an impairment of latent learning in a water-finding task and of learning-associated phosphorylation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and NR1 in the prefrontal cortex even after drug withdrawal. The infusion of a CaMKII inhibitor and NR1 antisense oligonucleotide into the prefrontal cortex produced an impairment of latent learning and decrease of learning-associated phosphorylation of CaMKII, which were observed in the PCP-treated mice. Exogenous NMDA-induced CaMKII activation was not observed in slices of the prefrontal cortex prepared from mice treated repeatedly with PCP. The potentiation of NMDA receptor function by the infusion of glycine into the prefrontal cortex ameliorated these impairments in mice treated repeatedly with PCP. The high potassium-stimulated release of dopamine from the prefrontal cortex was less extensive in the PCP-treated than saline-treated mice. The infusion of a dopamine-D1 receptor agonist into the prefrontal cortex attenuated the impairment of latent learning and decrease of learning-associated NR1 phosphorylation in the PCP-treated mice, suggesting a functional linkage between glutamatergic and dopaminergic signaling. These findings indicate that repeated PCP treatment impairs latent learning through a prefrontal cortical dysfunction of NMDA-CaMKII signaling, which is associated with dopaminergic hypofunction.
Mol Pharmacol 2007 Jun
PMID:Involvement of a dysfunctional dopamine-D1/N-methyl-d-aspartate-NR1 and Ca2+/calmodulin-dependent protein kinase II pathway in the impairment of latent learning in a model of schizophrenia induced by phencyclidine. 1734 53

We aimed to define the relative contribution of both PKA and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) cascades to the phosphorylation of RyR2 and the activity of the channel during beta-adrenergic receptor (betaAR) stimulation. Rat hearts were perfused with increasing concentrations of the beta-agonist isoproterenol in the absence and the presence of CaMKII inhibition. CaMKII was inhibited either by preventing the Ca(2+) influx to the cell by low [Ca](o) plus nifedipine or by the specific inhibitor KN-93. We immunodetected RyR2 phosphorylated at Ser2809 (PKA and putative CaMKII site) and at Ser2815 (CaMKII site) and measured [(3)H]-ryanodine binding and fast Ca(2+) release kinetics in sarcoplasmic reticulum (SR) vesicles. SR vesicles were isolated in conditions that preserved the phosphorylation levels achieved in the intact heart and were actively and equally loaded with Ca(2+). Our results demonstrated that Ser2809 and Ser2815 of RyR2 were dose-dependently phosphorylated under betaAR stimulation by PKA and CaMKII, respectively. The isoproterenol-induced increase in the phosphorylation of Ser2815 site was prevented by the PKA inhibitor H-89 and mimicked by forskolin. CaMKII-dependent phosphorylation of RyR2 (but not PKA-dependent phosphorylation) was responsible for the beta-induced increase in the channel activity as indicated by the enhancement of the [(3)H]-ryanodine binding and the velocity of fast SR Ca(2+) release. The present results show for the first time a dose-dependent increase in the phosphorylation of Ser2815 of RyR2 through the PKA-dependent activation of CaMKII and a predominant role of CaMKII-dependent phosphorylation of RyR2, over that of PKA-dependent phosphorylation, on SR-Ca(2+) release during betaAR stimulation.
J Mol Cell Cardiol 2007 Sep
PMID:Ca2+/calmodulin kinase II increases ryanodine binding and Ca2+-induced sarcoplasmic reticulum Ca2+ release kinetics during beta-adrenergic stimulation. 1764 48

By fusing the CaMKII-inhibitory peptide AIP to GFP, we constructed a specific and effective CaMKII inhibitor, GFP-AIP. Expression of GFP-AIP and/or dominant-inhibitory CaMKIV in cultured neonatal rat spiral ganglion neurons (SGNs) shows that CaMKII and CaMKIV act additively and in parallel to mediate the prosurvival effect of depolarization. Depolarization or expression of constitutively active CaMKII functionally inactivates Bad, indicating that this is one means by which CaMKII promotes neuronal survival. CaMKIV, but not CaMKII, requires CREB to promote SGN survival, consistent with the exclusively nuclear localization of CaMKIV and indicating that the principal prosurvival function of CaMKIV is activation of CREB. Consistent with this, a constitutively active CREB construct that provides a high level of CREB activity promotes SGN survival, although low levels of CREB activity did not do so. Also, in apoptotic SGNs, activation of CREB by depolarization is disabled, presumably as part of a cellular commitment to apoptosis.
Mol Cell Neurosci 2007 Sep
PMID:CaMKII and CaMKIV mediate distinct prosurvival signaling pathways in response to depolarization in neurons. 1765 87

Calcium/calmodulin dependent protein kinase II delta C (CaMKIIdelta(C)) and the EF-hand Ca(2+)-binding protein, sorcin have both been shown to regulate the excitation-contraction coupling process. This study explores the possibility that these two proteins interact directly and, as a result of this interaction, modulate cardiac calcium handling. Two independent methods (surface plasmon resonance (SPR) and overlay assays) were used to determine whether CaMKIIdelta(C) and sorcin interacted in a direct manner. The nature of this interaction was explored by (i) examining the effects of sorcin on CaMKIIdelta(C) activity using a selective kinase assay and (ii) studying whether sorcin was a substrate for CaMKIIdelta(C) using autoradiography. Ryanodine binding assays on mouse ventricular cardiomyocytes were used to determine specific functional effects of this interaction. SPR studies suggested that sorcin interacts with CaMKIIdelta(C) in a concentration-dependent manner. This interaction occurs in the presence of Ca(2+) and in the presence or absence of calmodulin (CaM). Overlay assays confirmed the existence of this interaction. Further experiments suggested that this interaction is reciprocal. Firstly, sorcin significantly inhibited both recombinant and native CaMKIIdelta(C) activity to similar extents. Secondly, sorcin was phosphorylated by CaMKIIdelta(C). Thirdly, sorcin inhibition of CaMKII activity occurred under conditions where sorcin remained dephosphorylated. Functionally, CaMKIIdelta(C)-mediated phosphorylation of sorcin served to abolish the inhibitory effect of sorcin on ryanodine receptor (RyR(2)) open probability (Po). Since both proteins are capable of directly modulating RyR(2) activity, this interaction may serve as an additional or alternative indirect route by which both proteins can regulate RyR(2) opening status in cardiac myocytes.
J Mol Cell Cardiol 2007 Oct
PMID:Interaction of calcium/calmodulin-dependent protein kinase IIdeltaC with sorcin indirectly modulates ryanodine receptor function in cardiac myocytes. 1770 98

Ca(2+)/calmodulin (CaM)-dependent protein kinase II (CaMKII) is a major mediator of cellular Ca(2+) signaling. Several inhibitors are commonly used to study CaMKII function, but these inhibitors all lack specificity. CaM-KIIN is a natural, specific CaMKII inhibitor protein. CN21 (derived from CaM-KIIN amino acids 43-63) showed full specificity and potency of CaMKII inhibition. CNs completely blocked Ca(2+)-stimulated and autonomous substrate phosphorylation by CaMKII and autophosphorylation at T305. However, T286 autophosphorylation (the autophosphorylation generating autonomous activity) was only mildly affected. Two mechanisms can explain this unusual differential inhibitor effect. First, CNs inhibited activity by interacting with the CaMKII T-site (and thereby also interfered with NMDA-type glutamate receptor binding to the T-site). Because of this, the CaMKII region surrounding T286 competed with CNs for T-site interaction, whereas other substrates did not. Second, the intersubunit T286 autophosphorylation requires CaM binding both to the "kinase" and the "substrate" subunit. CNs dramatically decreased CaM dissociation, thus facilitating the ability of CaM to make T286 accessible for phosphorylation. Tat-fusion made CN21 cell penetrating, as demonstrated by a strong inhibition of filopodia motility in neurons and insulin secrection from isolated Langerhans' islets. These results reveal the inhibitory mechanism of CaM-KIIN and establish a powerful new tool for dissecting CaMKII function.
Mol Biol Cell 2007 Dec
PMID:Dual mechanism of a natural CaMKII inhibitor. 1794 5

Recovery of intracellular Ca transients and fractional shortening during late phase acidosis are suggested to be associated with CaMKII-dependent processes of which phospholamban (PLB) phosphorylation may play an important role. To test whether increased expression levels of CaMKII may further enhance recovery, we investigated myocytes from CaMKIIdelta(C) transgenic (TG) mice (cytosolic localized CaMKII) having heart failure vs. wild-type littermates (WT). Furthermore, mouse and rabbit myocytes overexpressing CaMKIIdelta(C) using adenovirus-mediated gene transfer (vs. LacZ control) were investigated. Fractional shortening (% vs. resting cell length, % RCL) was assessed during control conditions (pH 7.4) and during acidosis (pH 6.5). Ca transients were measured using fluo-3 (DeltaF/F(0), 10 microM). In WT mouse myocytes, fractional shortening clearly recovered by 90% from 4.6+/-0.6 to 7.2+/-0.7% RCL during late acidosis. In parallel, Ca transients increased from 2.01+/-0.11 to 2.33+/-0.15 DeltaF/F(0). When blocking CaMKII (KN-93, 1 microM), recovery of Ca transients and shortening could be completely abolished. In contrast, in CaMKIIdelta(C) TG mouse myocytes shortening recovered only by 32% from 3.4+/-0.6 to 4.4+/-0.5% RCL (P<0.05 vs. WT using ANOVA). In parallel, Ca transients increased only slightly from 1.75+/-0.15 to 1.84+/-0.13 DeltaF/F(0) (P<0.05 vs. WT using ANOVA). In accordance, SR Ca content (measured by caffeine contractures, 10 mM) in WT significantly increased during late acidosis but not in CaMKIIdelta(C) TG mice. In contrast, in mouse and rabbit myocytes overexpressing CaMKIIdelta(C) by means of adenovirus-mediated gene transfer, recovery of fractional shortening and Ca transients was not impaired during late acidosis but even slightly improved vs. LacZ control (P<0.05 vs. CaMKIIdelta(C) using ANOVA for mouse and rabbit myocytes). This was associated with significantly increased SR Ca content during late acidosis in CaMKIIdelta(C) as compared to LacZ. CaMKII-dependent PLB Thr-17 phosphorylation, contributing to increased SR Ca uptake, was significantly increased in CaMKIIdelta(C) transfected rabbit myocytes vs. LacZ in the light of unchanged SR Ca ATPase and PLB protein expression. CaMKII inhibition completely prevented recovery of all parameters in both CaMKIIdelta(C) and LacZ. In summary and in contrast to our initial hypothesis, we showed for the first time that TG CaMKIIdelta(C) overexpression (i.e., chronic overexpression) in mice with heart failure clearly resulted in impaired recovery associated with impaired SR Ca loading during late acidosis vs. WT. This may be due to decreased SR Ca ATPase and PLB expression as reported previously. In contrast, adenovirus-mediated gene transfer of CaMKIIdelta(C) in mouse and rabbit myocytes (i.e., acute overexpression) did not result in impaired but even slightly improved recovery associated with increased SR Ca load during late acidosis as compared to LacZ. This most likely was due to higher PLB Thr-17 phosphorylation in CaMKIIdelta(C) myocytes. In conclusion, possible beneficial effects by therapeutical CaMKIIdelta(C) stimulation on the ability to recover from acidosis may be challenged by altered expression levels of its target proteins and should be carefully considered.
J Mol Cell Cardiol 2007 Dec
PMID:Effects on recovery during acidosis in cardiac myocytes overexpressing CaMKII. 1795 Jul 50

CaMKII is a calcium and calmodulin-activated kinase that has been shown to regulate learning and memory in the brain, and contractility in blood vessels. Following Ca activation, CaMKII autophosphorylates, gaining a calcium-independent autonomous activity that reflects a molecular memory of having previously come into contact with calcium. The present study addresses whether the molecular memory properties of CaMKII are involved in the modulation of sustained vascular tone. We demonstrate a history-dependence of alpha agonist-induced vascular tone and show that CaMKII activation in vascular cells is also history dependent. Autophosphorylation of Thr287, which is classically associated with autonomous activity, does not persist during tone maintenance after transient increases in intracellular calcium levels. However, we have found that another site, Thr305, known from in vitro studies to be inhibitory, is regulated by alpha agonists in that the inhibitory action is removed, thus leading to a delayed reactivation of CaMKII as measured by Thr287 phosphorylation. By the use of a small molecule CaMKII inhibitor (KN93) as well as a decoy peptide (autoinhibitory peptide; AIP) we show a cause and effect relationship between CaMKII reactivation and sustained vascular tone maintenance. Thus, it appears that a complex interplay between the regulation of Thr305 and Thr287 provides a novel mechanism by which a history-dependence is developed and contributes to a new facet of molecular memory for CaMKII of relevance to vascular tone maintenance.
J Cell Mol Med
PMID:CaMKIIT287 and T305 regulate history-dependent increases in alpha agonist-induced vascular tone. 1808 85

Auto-antibodies against the beta(1)-adrenoceptors are present in 30-40% of patients with dilated cardiomyopathy. Recently, a synthetic peptide corresponding to a sequence of the second extracellular loop of the human beta(1)-adrenoceptor (beta(1)-EC(II)) has been shown to produce endoplasmic reticulum (ER) stress, myocyte apoptosis and cardiomyopathy in immunized rabbits. To study the direct cardiac effects of anti-beta(1)-EC(II) antibody in intact animals and if they are mediated via beta(1)-adrenoceptor stimulation, we administered IgG purified from beta(1)-EC(II)-immunized rabbits to recombination activating gene 2 knock-out (Rag2(-/-)) mice every 2 weeks with and without metoprolol treatment. Serial echocardiography and cardiac catheterization showed that beta(1)-EC(II) IgG reduced cardiac systolic function after 3 months. This was associated with increase in heart weight, myocyte apoptosis, activation of caspase-3, -9 and -12, and increased ER stress as evidenced by upregulation of GRP78 and CHOP and cleavage of ATF6. The Rag2(-/-) mice also exhibited increased phosphorylation of CaMKII and p38 MAPK. Metoprolol administration, which attenuated the phosphorylation of CaMKII and p38 MAPK, reduced the ER stress, caspase activation and cell death. Finally, we employed the small-interfering RNA technology to reduce caspase-12 in cultured rat cardiomyocytes. This reduced not only the increase of cleaved caspase-12 but also of the number of myocyte apoptosis produced by beta(1)-EC(II) IgG. Thus, we conclude that ER stress plays an important role in cell death and cardiac dysfunction in beta(1)-EC(II) IgG cardiomyopathy, and the effects of beta(1)-EC(II) IgG are mediated via the beta(1)-adrenergic receptor.
J Mol Cell Cardiol 2008 Feb
PMID:Adoptive passive transfer of rabbit beta1-adrenoceptor peptide immune cardiomyopathy into the Rag2-/- mouse: participation of the ER stress. 1815 31

Regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) in airway smooth muscle (ASM) during agonist stimulation involves sarcoplasmic reticulum (SR) Ca(2+) release and reuptake. The sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) is key to replenishment of SR Ca(2+) stores. We examined regulation of SERCA in porcine ASM: our hypothesis was that the regulatory protein phospholamban (PLN) and the calmodulin (CaM)-CaM kinase (CaMKII) pathway (both of which are known to regulate SERCA in cardiac muscle) play a role. In porcine ASM microsomes, we examined the expression and extent of PLN phosphorylation after pharmacological inhibition of CaM (with W-7) vs. CaMKII (with KN-62/KN-93) and found that PLN is phosphorylated by CaMKII. In parallel experiments using enzymatically dissociated single ASM cells loaded with the Ca(2+) indicator fluo 3 and imaged using fluorescence microscopy, we measured the effects of PLN small interfering RNA, W-7, and KN-62 on [Ca(2+)](i) responses to ACh and direct SR stimulation. PLN small interfering RNA slowed the rate of fall of [Ca(2+)](i) transients to 1 microM ACh, as did W-7 and KN-62. The two inhibitors additionally slowed reuptake in the absence of PLN. In other cells, preexposure to W-7 or KN-62 did not prevent initiation of ACh-induced [Ca(2+)](i) oscillations (which were previously shown to result from repetitive SR Ca(2+) release/reuptake). However, when ACh-induced [Ca(2+)](i) oscillations reached steady state, subsequent exposure to W7 or KN-62 decreased oscillation frequency and amplitude and slowed the fall time of [Ca(2+)](i) transients, suggesting SERCA inhibition. Exposure to W-7 completely abolished ongoing ACh-induced [Ca(2+)](i) oscillations in some cells. Preexposure to W-7 or KN-62 did not affect caffeine-induced SR Ca(2+) release, indicating that ryanodine receptor channels were not directly inhibited. These data indicate that, in porcine ASM, the CaM-CaMKII pathway regulates SR Ca(2+) reuptake, potentially through altered PLN phosphorylation.
Am J Physiol Lung Cell Mol Physiol 2008 Apr
PMID:Regulation of sarcoplasmic reticulum Ca2+ reuptake in porcine airway smooth muscle. 1824 64


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