scholarly journals Inhibition of Calcium/Calmodulin-dependent Protein Kinase Kinase by Protein 14-3-3

2004 ◽  
Vol 279 (50) ◽  
pp. 52191-52199 ◽  
Author(s):  
Monika A. Davare ◽  
Takeo Saneyoshi ◽  
Eric S. Guire ◽  
Sean C. Nygaard ◽  
Thomas R. Soderling
Keyword(s):  
Protein Kinase ◽  
Signaling Pathways ◽  
Hippocampal Slices ◽  
Phosphorylation Site ◽  
Site Directed Mutagenesis ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Signal ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein

Intracellular calcium concentrations regulate diverse cellular events including cytoskeletal dynamics, gene transcription, and synaptic plasticity. The calcium signal is transduced in part by the calcium/calmodulin-dependent protein kinase (CaMK) cascade that is comprised of CaMK kinase (CaMKK) and its primary downstream substrates, CaMKI and CaMKIV. The CaMK cascade also participates in cross-talk with other signaling pathways: CaMKK/CaMKI can activate the mitogen-activated protein kinase pathway and cAMP-dependent protein kinase (PKA) can directly phosphorylate two inhibitory sites (Thr108and Ser458) in CaMKK. Here we report an additional PKA-dependent regulation of CaMKK through its interaction with protein 14-3-3. CaMKK and 14-3-3 co-immunoprecipitated from co-transfected heterologous cells as well as from rat brain homogenate, and site-directed mutagenesis studies identified phospho-Ser74in CaMKK as the primary 14-3-3 binding site. In cultured rat hippocampal neurons and acute hippocampal slices this interaction was robustly stimulated by activation of PKA through forskolin treatment and was blocked by inhibition of PKA. Interaction of 14-3-3 with CaMKK had two regulatory consequencesin vitro. It directly inhibited CaMKK activity, and it also blocked dephosphorylation of Thr108, an inhibitory PKA phosphorylation site. In human embryonic kidney 293 cells transfected with CaMKK and stimulated with forskolin, co-transfection with 14-3-3 prevented dephosphorylation of Thr108to the same extent as did inhibition of protein phosphatases with okadaic acid. We conclude that binding of 14-3-3 to CaMKK stabilizes its inhibition by PKA-mediated phosphorylation, which may have important consequences in the regulation of CaMKI, CaMKIV, protein kinase B, and ERK signaling pathways.

scholarly journals p38 Mitogen-activated Protein Kinase-, Calcium-Calmodulin–dependent Protein Kinase-, and Calcineurin-mediated Signaling Pathways Transcriptionally Regulate Myogenin Expression

2002 ◽  
Vol 13 (6) ◽  
pp. 1940-1952 ◽  
Author(s):  
Qing Xu ◽  
Lu Yu ◽  
Lanying Liu ◽  
Ching Fung Cheung ◽  
Xue Li ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signaling Pathways ◽  
Histone Deacetylases ◽  
Mitogen Activated Protein Kinase ◽  
Cis Elements ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Mitogen Activated Protein ◽  
Rd Cells ◽  
Dependent Protein

In this report, we identify myogenin as an important transcriptional target under the control of three intracellular signaling pathways, namely, the p38 mitogen-activated protein kinase- (MAPK), calcium-calmodulin–dependent protein kinase- (CaMK), and calcineurin-mediated pathways, during skeletal muscle differentiation. Three cis-elements (i.e., the E box, myocyte enhancer factor [MEF] 2, and MEF3 sites) in the proximal myogenin promoter in response to these three pathways are defined. MyoD, MEF2s, and Six proteins, the trans-activators bound to these cis-elements, are shown to be activated by these signaling pathways. Our data support a model in which all three signaling pathways act in parallel but nonredundantly to control myogenin expression. Inhibition of any one pathway will result in abolished or reduced myogenin expression and subsequent phenotypic differentiation. In addition, we demonstrate that CaMK and calcineurin fail to activate MEF2s in Rhabdomyosarcoma-derived RD cells. For CaMK, we show its activation in response to differentiation signals and its effect on the cytoplasmic translocation of histone deacetylases 5 are not compromised in RD cells, suggesting histone deacetylases 5 cytoplasmic translocation is necessary but not sufficient, and additional signal is required in conjunction with CaMK to activate MEF2 proteins.

Mechanisms Underlying Dedepression of Synaptic NMDA Receptors in the Hippocampus

2008 ◽  
Vol 99 (1) ◽  
pp. 254-263 ◽  
Author(s):  
Wade Morishita ◽  
Robert C. Malenka
Keyword(s):  
Protein Kinase ◽  
Metabotropic Glutamate Receptors ◽  
Pyramidal Cells ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Protein Kinase ◽  
Metabotropic Glutamate ◽  
Calcium Calmodulin Dependent ◽  
Ca1 Region ◽  
Dependent Protein ◽  
Synaptic Responses

N-Methyl-d-aspartate receptor (NMDAR)–mediated synaptic responses in hippocampal CA1 pyramidal cells are depressed during NMDAR-dependent long-term depression (LTD) due to mechanisms, in part, distinct from those underlying LTD of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)–mediated synaptic responses. The mechanisms underlying dedepression of synaptic NMDARs, however, are not known. We find that dedepression of NMDAR-mediated synaptic responses in the CA1 region of the rat hippocampus is input specific and does not require synaptic stimulation to be maintained. The induction of dedepression does not require activation of metabotropic glutamate receptors, L-type Ca2+ channels, or release of Ca2+ from intracellular stores. It does, however, rely on activation of NMDARs. In contrast to the dedepression of AMPAR-mediated synaptic responses, dedepression of NMDAR-mediated synaptic responses does not depend on activation of calcium/calmodulin-dependent protein kinase II, protein kinase C, cAMP-dependent protein kinase, or Src kinases. However, dedepression of synaptic NMDARs is significantly impaired by inhibitors of mitogen-activated protein kinase signaling. Specifically, inhibitors of extracellular signal-regulated kinase 1/2 prevented normal dedepression of synaptic NMDARs by a mechanism that did not require protein synthesis. These results provide further evidence that synaptic NMDARs can be bidirectionally modified by activity but by mechanisms distinct from those responsible for the activity-dependent, bidirectional modulation of synaptic AMPARs.

Calcium/calmodulin-dependent protein kinase II clusters in adult rat hippocampal slices

Neuroscience ◽  
2002 ◽  
Vol 115 (2) ◽  
pp. 435-440 ◽  
Author(s):  
J.-H. Tao-Cheng ◽  
L. Vinade ◽  
L.D. Pozzo-Miller ◽  
T.S. Reese ◽  
A. Dosemeci
Keyword(s):  
Protein Kinase ◽  
Hippocampal Slices ◽  
Dependent Protein Kinase ◽  
Adult Rat ◽  
Calcium Calmodulin Dependent ◽  
Protein Kinase Ii ◽  
Dependent Protein

scholarly journals Calcium/calmodulin-dependent protein kinase IIdelta associates with the ryanodine receptor complex and regulates channel function in rabbit heart

2004 ◽  
Vol 377 (2) ◽  
pp. 357-366 ◽  
Author(s):  
Susan CURRIE ◽  
Christopher M. LOUGHREY ◽  
Margaret-Anne CRAIG ◽  
Godfrey L. SMITH
Keyword(s):  
Protein Kinase ◽  
Sarcoplasmic Reticulum ◽  
Critical Role ◽  
Phosphorylation Site ◽  
Specific Inhibitor ◽  
Ventricular Myocardium ◽  
Inhibitory Peptide ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein

Cardiac ryanodine receptors (RyR2s) play a critical role in excitation–contraction coupling by providing a pathway for the release of Ca2+ from the sarcoplasmic reticulum into the cytosol. RyR2s exist as macromolecular complexes that are regulated via binding of Ca2+ and protein phosphorylation/dephosphorylation. The present study examined the association of endogenous CaMKII (calcium/calmodulin-dependent protein kinase II) with the RyR2 complex and whether this enzyme could modulate RyR2 function in isolated rabbit ventricular myocardium. Endogenous phosphorylation of RyR2 was verified using phosphorylation site-specific antibodies. Co-immunoprecipitation studies established that RyR2 was physically associated with CaMKIIδ. Quantitative assessment of RyR2 protein was performed by [3H]ryanodine binding to RyR2 immunoprecipitates. Parallel kinase assays allowed the endogenous CaMKII activity associated with these immunoprecipitates to be expressed relative to the amount of RyR2. The activity of RyR2 in isolated cardiac myocytes was measured in two ways: (i) RyR2-mediated Ca2+ release (Ca2+ sparks) using confocal microscopy and (ii) Ca2+-sensitive [3H]ryanodine binding. These studies were performed in the presence and absence of AIP (autocamtide-2-related inhibitory peptide), a highly specific inhibitor of CaMKII. At 1 µM AIP Ca2+ spark duration, frequency and width were decreased significantly. Similarly, 1 µM AIP decreased [3H]ryanodine binding. At 5 µM AIP, a more profound inhibition of Ca2+ sparks and a decrease in [3H]ryanodine binding was observed. Separate measurements showed that AIP (1–5 µM) did not affect sarcoplasmic reticulum Ca2+-ATPase-mediated Ca2+ uptake. These results suggest the existence of an endogenous CaMKIIδ that associates directly with RyR2 and specifically modulates RyR2 activity.

scholarly journals Tau protein is phosphorylated by cyclic AMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase II within its microtubule-binding domains at Ser-262 and Ser-356

1996 ◽  
Vol 316 (2) ◽  
pp. 655-660 ◽  
Author(s):  
Joel M. LITERSKY ◽  
Gail V. W. JOHNSON ◽  
Ross JAKES ◽  
Michel GOEDERT ◽  
Michael LEE ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Tau Protein ◽  
Paired Helical Filaments ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Binding Domains ◽  
Protein Kinase Ii ◽  
Dependent Protein

Phosphorylation of tau protein at Ser-262 has been shown to diminish its ability to bind to taxol-stabilized microtubules. The paired helical filaments (PHFs) found in Alzheimer's disease brain are composed of PHF-tau, which is hyperphosphorylated at multiple sites including Ser-262. However, protein kinase(s) able to phosphorylate this site are still under investigation. In this study, the ability of cyclic AMP-dependent protein kinase (cAMP-PK) and calcium/calmodulin-dependent protein kinase II (CaMKII) to phosphorylate tau at Ser-262, as well as Ser-356, is demonstrated by use of a monoclonal antibody (12E8) which has been shown to recognize tau when these sites are phosphorylated. Cleavage of cAMP-PK-phosphorylated tau at cysteine residues by 2-nitro-5-thiocyanobenzoic acid, which cuts the protein into essentially two fragments and separates Ser-262 from Ser-356, revealed that cAMP-PK phosphorylates both Ser-262 and Ser-356. In addition, phosphorylation with cAMP-PK or CaMKII of recombinant tau in which Ser-262, Ser-356 or both had been mutated to alanines, clearly demonstrated that cAMP-PK and CaMKII were able to phosphorylate both sites. Mitogen-activated protein kinase or protein kinase C did not phosphorylate tau at Ser-262 and/or Ser-356. Finally, evidence is presented that phosphorylation of both these sites occurs in cultured nerve cells under certain conditions, indicating their potential physiological relevance.

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