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.

iNOS regulation by calcium/calmodulin-dependent protein kinase II in vascular smooth muscle

2007 ◽  
Vol 292 (6) ◽  
pp. H2634-H2642 ◽  
Author(s):  
Rachel J. Jones ◽  
David Jourd'heuil ◽  
John C. Salerno ◽  
Susan M. E. Smith ◽  
Harold A. Singer
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Vascular Smooth Muscle ◽  
Resting Cells ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Cytokine Induction ◽  
Calcium Calmodulin Dependent ◽  
Protein Kinase Ii ◽  
Dependent Protein

Nitric oxide synthase (NOS) expression is regulated transcriptionally in response to cytokine induction and posttranslationally by palmitoylation and trafficking into perinuclear aggresome-like structures. We investigated the effects of multifunctional calcium/calmodulin-dependent protein kinase II protein kinase (CaMKII) on inducible NOS (iNOS) trafficking in cultured rat aortic vascular smooth muscle cells (VSMCs). Immunofluorescence and confocal microscopy demonstrated colocalization of iNOS and CaMKIIδ2 with a perinuclear distribution and concentration in aggresome-like structures identified by colocalization with γ-tubulin. Furthermore, CaMKIIδ2 coimmunoprecipitated with iNOS in a CaMKII activity-dependent manner. Addition of Ca2+-mobilizing stimuli expected to activate CaMKII; a purinergic agonist (UTP) or calcium ionophore (ionomycin) caused a general redistribution of iNOS from cytosolic to membrane and nuclear fractions. Similarly, adenoviral expression of a constitutively active CaMKIIδ2 mutant altered iNOS localization, shifting iNOS from the cytosolic fraction. Suppression of CaMKIIδ2 using an adenovirus expressing a short hairpin, small interfering RNA increased nuclear iNOS localization in resting cells but inhibited ionomycin-induced translocation of iNOS to the nucleus. Following addition of these chronic and acute CaMKII modulators, there were fewer aggresome-like structures containing iNOS. All of the treatments that chronically affected CaMKII activity or expression significantly inhibited iNOS-specific activity following cytokine induction. The results suggest that CaMKIIδ2 may be an important regulator of iNOS trafficking and activity in VSMCs.

scholarly journals Characterization of ATM Expression, Localization, and Associated DNA-dependent Protein Kinase Activity

1998 ◽  
Vol 9 (9) ◽  
pp. 2361-2374 ◽  
Author(s):  
Dennis P. Gately ◽  
James C. Hittle ◽  
Gordon K. T. Chan ◽  
Tim J. Yen
Keyword(s):  
Dna Damage ◽  
Protein Kinase ◽  
Ataxia Telangiectasia ◽  
Kinase Activity ◽  
Human Fibroblasts ◽  
Protein Kinase Activity ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Atm Protein

Ataxia telangiectasia–mutated gene (ATM) is a 350-kDa protein whose function is defective in the autosomal recessive disorder ataxia telangiectasia (AT). Affinity-purified polyclonal antibodies were used to characterize ATM. Steady-state levels of ATM protein varied from undetectable in most AT cell lines to highly expressed in HeLa, U2OS, and normal human fibroblasts. Subcellular fractionation showed that ATM is predominantly a nuclear protein associated with the chromatin and nuclear matrix. ATM protein levels remained constant throughout the cell cycle and did not change in response to serum stimulation. Ionizing radiation had no significant effect on either the expression or distribution of ATM. ATM immunoprecipitates from HeLa cells and the human DNA-dependent protein kinase null cell line MO59J, but not from AT cells, phosphorylated the 34-kDa subunit of replication protein A (RPA) complex in a single-stranded and linear double-stranded DNA–dependent manner. Phosphorylation of p34 RPA occurred on threonine and serine residues. Phosphopeptide analysis demonstrates that the ATM-associated protein kinase phosphorylates p34 RPA on similar residues observed in vivo. The DNA-dependent protein kinase activity observed for ATM immunocomplexes, along with the association of ATM with chromatin, suggests that DNA damage can induce ATM or a stably associated protein kinase to phosphorylate proteins in the DNA damage response pathway.

scholarly journals Conduction in the right and left ventricle is differentially regulated by protein kinases and phosphatases: implications for arrhythmogenesis

2019 ◽  
Vol 316 (6) ◽  
pp. H1507-H1527 ◽  
Author(s):  
Alexey V. Zaitsev ◽  
Natalia S. Torres ◽  
Keiko M. Cawley ◽  
Amira D. Sabry ◽  
Junco S. Warren ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Specific Expression ◽  
Stress Kinases ◽  
Calcium Calmodulin Dependent ◽  
Protein Kinase Ii ◽  
Dependent Protein ◽  
The Right ◽  
Ventricular Conduction

The “stress” kinases cAMP-dependent protein kinase (PKA) and calcium/calmodulin-dependent protein kinase II (CaMKII), phosphorylate the Na+ channel Nav1.5 subunit to regulate its function. However, how the channel regulation translates to ventricular conduction is poorly understood. We hypothesized that the stress kinases positively and differentially regulate conduction in the right (RV) and the left (LV) ventricles. We applied the CaMKII blocker KN93 (2.75 μM), PKA blocker H89 (10 μM), and broad-acting phosphatase blocker calyculin (30 nM) in rabbit hearts paced at a cycle length (CL) of 150-8,000 ms. We used optical mapping to determine the distribution of local conduction delays (inverse of conduction velocity). Control hearts exhibited constant and uniform conduction at all tested CLs. Calyculin (15-min perfusion) accelerated conduction, with greater effect in the RV (by 15.3%) than in the LV (by 4.1%; P < 0.05). In contrast, both KN93 and H89 slowed down conduction in a chamber-, time-, and CL-dependent manner, with the strongest effect in the RV outflow tract (RVOT). Combined KN93 and H89 synergistically promoted conduction slowing in the RV (KN93: 24.7%; H89: 29.9%; and KN93 + H89: 114.2%; P = 0.0016) but not the LV. The progressive depression of RV conduction led to conduction block and reentrant arrhythmias. Protein expression levels of both the CaMKII-δ isoform and the PKA catalytic subunit were higher in the RVOT than in the apical LV ( P < 0.05). Thus normal RV conduction requires a proper balance between kinase and phosphatase activity. Dysregulation of this balance due to pharmacological interventions or disease is potentially proarrhythmic. NEW & NOTEWORTHY We show that uniform ventricular conduction requires a precise physiological balance of the activities of calcium/calmodulin-dependent protein kinase II (CaMKII), PKA, and phosphatases, which involves region-specific expression of CaMKII and PKA. Inhibiting CaMKII and/or PKA activity elicits nonuniform conduction depression, with the right ventricle becoming vulnerable to the development of conduction disturbances and ventricular fibrillation/ventricular tachycardia.

Cytoskeletal-like Filaments of Ca2+-Calmodulin-Dependent Protein Kinase II Are Formed in a Regulated and Zn2+-Dependent Manner

Biochemistry ◽  
2017 ◽  
Vol 56 (15) ◽  
pp. 2149-2160 ◽  
Author(s):  
Laurel Hoffman ◽  
Lin Li ◽  
Emil Alexov ◽  
Hugo Sanabria ◽  
M. Neal Waxham
Keyword(s):  
Protein Kinase ◽  
Dependent Manner ◽  
Dependent Protein Kinase ◽  
Protein Kinase Ii ◽  
Dependent Protein

scholarly journals Axokinin phosphorylation by cAMP-dependent protein kinase is sufficient for activation of sperm flagellar motility.

1986 ◽  
Vol 103 (2) ◽  
pp. 649-655 ◽  
Author(s):  
J S Tash ◽  
H Hidaka ◽  
A R Means
Keyword(s):  
Protein Kinase ◽  
De Novo ◽  
Protein Kinase Activity ◽  
Dependent Manner ◽  
Flagellar Motility ◽  
Dependent Protein Kinase ◽  
Camp Dependent Protein Kinase ◽  
Heat Stable ◽  
Protein Kinase N ◽  
Dependent Protein

Using a selective inhibitor of cAMP-dependent protein kinase, N-[2(methylamino)ethyl]-5-isoquinolinesulfonamide (H-8), the requirement for cAMP-dependent phosphoproteins in the initiation of dog sperm flagellar motility was examined. H-8 inhibited motility of live as well as reactivated sperm in a dose-dependent manner. The half-maximal inhibition of reactivated motility (32 microM) paralleled the inhibition of pure catalytic subunit of cAMP-dependent protein kinase (50 microM) measured under the same conditions. H-8 inhibited protein phosphorylation both in whole models and in isolated Nonidet P-40 (NP-40) extracts of sperm. Axokinin, the heat-stable NP-40-soluble protein whose phosphorylation is required for flagellar reactivation, represented 97% of the de novo phosphate incorporation in the NP-40 extract after stimulation by cAMP. 500 microM H-8 inhibited axokinin phosphorylation by 87%. When sperm were reactivated in the presence of up to 5 mM H-8 with NP-40 extract that had been prephosphorylated with cAMP-dependent protein kinase, then neither cAMP nor cAMP-dependent protein kinase activity was required for full flagellar reactivation. If sperm were rendered completely immotile by pretreatment with H-8, then the resulting model remained immotile in the continued presence of H-8 unless prephosphorylated axokinin was added. These results suggest that phosphorylated axokinin is not only required for flagellar reactivation but is sufficient as well.

Possible site of action of 5-hydroperoxyeicosatetraenoic acid derived from arachidonic acid in ACTH-stimulated steroidogenesis in rat adrenal glands

1990 ◽  
Vol 125 (1) ◽  
pp. 89-96 ◽  
Author(s):  
K. Mikami ◽  
M. Omura ◽  
Y. Tamura ◽  
S. Yoshida
Keyword(s):  
Kinase Activity ◽  
Specific Inhibitor ◽  
Protein Kinase Activity ◽  
Dependent Manner ◽  
Cholesterol Accumulation ◽  
Dependent Protein Kinase ◽  
Site Of Action ◽  
Dependent Protein ◽  
Hydroperoxyeicosatetraenoic Acid ◽  
Dose Dependent

ABSTRACT The site of action of 5-hydroperoxyeicosatetraenoic acid (5-HPETE) in ACTH-induced stimulation of steroidogenesis was examined in rat adrenocortical fasciculata cells. Prior addition of AA861, a specific inhibitor of 5-lipoxygenase, had no significant effect on cyclic AMP-dependent protein kinase activity and cholesterol esterase activities, when stimulated by ACTH in adrenocortical cells, compared with that stimulated by ACTH alone. Cholesterol accumulation in the mitochondria of cells treated with ACTH and cycloheximide was also not altered by pretreatment with AA861. We found, however, that pregnenolone formation, stimulated by ACTH, decreased in a dose-dependent manner when cells were pretreated with AA861. The inhibition of ACTH-stimulated pregnenolone formation by treatment with AA861 was restored only by prior addition of 5-HPETE. Furthermore, addition of AA861 also did not affect the conversion of pregnenolone into corticosterone. In conclusion, 5-HPETE may act at the level of the mitochondria in ACTH-induced steroidogenesis in rat adrenal fasciculata cells. Journal of Endocrinology (1990) 125, 89–96

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