scholarly journals CaMKII Potentiates Store-Operated Ca2+ Entry Through Enhancing STIM1 Aggregation and Interaction with Orai1

2018 ◽  
Vol 46 (3) ◽  
pp. 1042-1054 ◽  
Author(s):  
Shu Li ◽  
Jingyi Xue ◽  
Zhipeng Sun ◽  
Tiantian Liu ◽  
Lane Zhang ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Confocal Microscopy ◽  
Specific Inhibitor ◽  
Potential Mechanism ◽  
Additional Insight ◽  
Dependent Protein Kinase ◽  
Store Depletion ◽  
Selective Channel ◽  
Dependent Protein ◽  
Insight Into

Background/Aims: Upon Ca2+ store depletion, stromal interaction molecule 1 (STIM1) oligomerizes, redistributes near plasmalemma to interact with Ca2+ selective channel-forming subunit (Orai1) and initiates store-operated Ca2+ entry (SOCE). Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a regulator of SOCE, but how CaMKII regulates SOCE remains obscure. Methods: Using Fura2, confocal microscopy, co-immunoprecipitation, specific blocker and overexpression/knockdown approaches, we evaluated STIM1 aggregation and its interaction with Orai1, and SOCE upon Ca2+ store depletion in thapsigargin (TG) treated HEK293 and HeLa cells. Results: Overexpression of CaMKIIδ enhanced TG-induced STIM1 co-localization and interaction with Orai1 as well as SOCE. In contrast, CaMKIIδ knockdown and a specific inhibitor of CaMKII suppressed them. In addition, overexpression or knockdown of CaMKIIδ in TG treated cells exhibited increased or reduced STIM1 clustering and plasmalemma redistribution, respectively. Conclusion: CaMKII up-regulates SOCE by increasing STIM1 aggregation and interaction with Orai1. This study provides an additional insight into SOCE regulation and a potential mechanism for CaMKII involvement in some pathological situations through crosstalk with SOCE.

scholarly journals STO-609, a specific inhibitor of the Ca2+/calmodulin-dependent protein kinase kinase.

2003 ◽  
Vol 278 (6) ◽  
pp. 4368
Author(s):  
Hiroshi Tokumitsu ◽  
Hiroyuki Inuzuka ◽  
Yumi Ishikawa ◽  
Masahiko Ikeda ◽  
Ikutaro Saji ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Specific Inhibitor ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Protein Kinase Kinase

scholarly journals An Active C-Terminally Truncated Form of Ca2+/Calmodulin-Dependent Protein Kinase Phosphatase-N (CaMKP-N/PPM1E)

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Atsuhiko Ishida ◽  
Kumiko Tsumura ◽  
Megu Oue ◽  
Yasuhiro Takenaka ◽  
Yasushi Shigeri ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Expression System ◽  
Active Form ◽  
Specific Inhibitor ◽  
Proteolytic Processing ◽  
Disulfonic Acid ◽  
Truncated Form ◽  
Dependent Protein Kinase ◽  
Wheat Embryo ◽  
Dependent Protein

Ca2+/calmodulin-dependent protein kinase phosphatase (CaMKP/PPM1F) and its nuclear homolog CaMKP-N (PPM1E) are Ser/Thr protein phosphatases that belong to the PPM family. CaMKP-N is expressed in the brain and undergoes proteolytic processing to yield a C-terminally truncated form. The physiological significance of this processing, however, is not fully understood. Using a wheat-embryo cell-free protein expression system, we prepared human CaMKP-N (hCaMKP-N(WT)) and the truncated form, hCaMKP-N(1–559), to compare their enzymatic properties using a phosphopeptide substrate. The hCaMKP-N(1–559) exhibited a much higherVmaxvalue than the hCaMKP-N(WT) did, suggesting that the processing may be a regulatory mechanism to generate a more active species. The active form, hCaMKP-N(1–559), showed Mn2+or Mg2+-dependent phosphatase activity with a strong preference for phospho-Thr residues and was severely inhibited by NaF, but not by okadaic acid, calyculin A, or 1-amino-8-naphthol-2,4-disulfonic acid, a specific inhibitor of CaMKP. It could bind to postsynaptic density and dephosphorylate the autophosphorylated Ca2+/calmodulin-dependent protein kinase II. Furthermore, it was inactivated by H2O2treatment, and the inactivation was completely reversed by treatment with DTT, implying that this process is reversibly regulated by oxidation/reduction. The truncated CaMKP-N may play an important physiological role in neuronal cells.

scholarly journals Calcineurin Inhibitor, FK506, Prevents Reduction in the Binding Capacity of Cyclic AMP-Dependent Protein Kinase in Ischemic Gerbil Brain

1997 ◽  
Vol 17 (4) ◽  
pp. 412-420 ◽  
Author(s):  
Kortaro Tanaka ◽  
Yasuo Fukuuchi ◽  
Hiroyuki Nozaki ◽  
Eiichiro Nagata ◽  
Taro Kondo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Blood Vessels ◽  
Binding Capacity ◽  
Specific Inhibitor ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Dependent Protein Kinase ◽  
Arterial Blood ◽  
Dependent Protein

We examined the effects of FK506, a specific inhibitor of calcineurin, on the binding capacity of cyclic AMP-dependent protein kinase (cAMP-DPK) in gerbils subjected to 2-h cerebral hemispheric ischemia. FK506 (0.1 mg/kg) was infused intravenously at 15 min prior to the induction of ischemia by common carotid artery occlusion. The binding capacity of cAMP-DPK was evaluated by autoradiographic analysis of the cAMP binding, and cerebral blood flow (CBF) was measured by the [14C] iodoantipyrine method. In the sham-operated gerbils, FK506 significantly increased mean arterial blood pressure and tended to decrease CBF, suggesting that FK506 may constrict systemic blood vessels as well as cerebral blood vessels. On the other hand, cAMP binding was not altered by FK506 in the sham-operated gerbils. In the ischemia group of gerbils, FK506 prevented any significant reduction of cAMP binding in the hippocampus CA1 and cerebral cortices on the ischemic side, whereas it exerted no significant influence on the cAMP binding of the nonischemic side. The values of CBF were comparable between the vehicle-treated gerbils and FK506-treated gerbils in the ischemic regions. Preservation of cAMP binding indicates that intracellular signal transduction via cAMP-DPK can be maintained by FK506 despite ischemia, suggesting that this agent may be beneficial for reducing ischemic tissue damage.

scholarly journals Testosterone-induced relaxation of coronary arteries: activation of BKCa channels via the cGMP-dependent protein kinase

2012 ◽  
Vol 302 (1) ◽  
pp. H115-H123 ◽  
Author(s):  
Viju Deenadayalu ◽  
Yashoda Puttabyatappa ◽  
Alexander T. Liu ◽  
John N. Stallone ◽  
Richard E. White
Keyword(s):  
Nitric Oxide ◽  
Coronary Artery ◽  
Protein Kinase ◽  
Coronary Arteries ◽  
Specific Inhibitor ◽  
No Production ◽  
Channel Activity ◽  
Dependent Protein Kinase ◽  
Cgmp Dependent Protein Kinase ◽  
Dependent Protein

Androgens are reported to have both beneficial and detrimental effects on human cardiovascular health. The aim of this study was to characterize nongenomic signaling mechanisms in coronary artery smooth muscle (CASM) and define the ionic basis of testosterone (TES) action. TES-induced relaxation of endothelium-denuded porcine coronary arteries was nearly abolished by 20 nM iberiotoxin, a highly specific inhibitor of large-conductance, calcium-activated potassium (BKCa) channels. Molecular patch-clamp studies confirmed that nanomolar concentrations of TES stimulated BKCa channel activity by ∼100-fold and that inhibition of nitric oxide synthase (NOS) activity by NG-monomethyl-l-arginine nearly abolished this effect. Inhibition of nitric oxide (NO) synthesis or guanylyl cyclase activity also attenuated TES-induced coronary artery relaxation but did not alter relaxation due to 8-bromo-cGMP. Furthermore, we detected TES-stimulated NO production in porcine coronary arteries and in human CASM cells via stimulation of the type 1 neuronal NOS isoform. Inhibition of the cGMP-dependent protein kinase (PKG) attenuated TES-stimulated BKCa channel activity, and direct assay determined that TES increased activity of PKG in a concentration-dependent fashion. Last, the stimulatory effect of TES on BKCa channel activity was mimicked by addition of purified PKG to the cytoplasmic surface of a cell-free membrane patch from CASM myocytes (∼100-fold increase). These findings indicate that TES-induced relaxation of endothelium-denuded coronary arteries is mediated, at least in part, by enhanced NO production, leading to cGMP synthesis and PKG activation, which, in turn, opens BKCa channels. These findings provide a molecular mechanism that could help explain why androgens have been reported to relax coronary arteries and relieve angina pectoris.

scholarly journals Characterization of γ- and δ-subunits of Ca2+/calmodulin-dependent protein kinase II in rat gastric mucosal cell populations

1994 ◽  
Vol 297 (1) ◽  
pp. 157-162 ◽  
Author(s):  
P Mayer ◽  
M Möhlig ◽  
U Seidler ◽  
H Rochlitz ◽  
M Fährmann ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Signal Transmission ◽  
Specific Inhibitor ◽  
Protein Kinase Activity ◽  
Mucosal Cell ◽  
Specific Substrate ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein

We searched for the occurrence of a Ca2+/calmodulin-dependent protein kinase in rat gastric cell types as a likely member in the chain of gastrin- and muscarinic-receptor-mediated signal transmission. A Ca(2+)- and calmodulin-dependent phosphorylation of major 50, 60 and 100 kDa substrates was observed in parietal cell cytosol and a major 60 and 61 kDa protein doublet was found to bind 125I-calmodulin in 125I-calmodulin-gel overlays. A specific substrate of the multifunctional Ca2+/calmodulin-dependent protein kinase II, autocamtide II, was phosphorylated in a calmodulin-dependent manner. The specific inhibitor of this enzyme, KN-62, antagonized protein kinase activity. RNA extracted from gastric mucosal cells was shown to contain sequences of the gamma- and delta- but not alpha- and beta-subunits of the calmodulin-dependent kinase II, and mRNA of both subtypes was demonstrated in highly purified parietal, chief and mucous cells. A calmodulin-dependent kinase II composed of gamma- and delta-subunits is a likely mediator of Ca(2+)-dependent signal transmission in these populations of gastric cells.

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