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Susan E. Wellman - One of the best experts on this subject based on the ideXlab platform.
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Changes in [^3H]Forskolin Binding to Adenylate Cyclase and [^3H]Phorbol Dibutyrate Binding to Protein Kinase C in Pentobarbital Tolerant/Dependent Rats
Neurochemical Research, 1998Co-Authors: Susan E. WellmanAbstract:These studies were designed to examine the effect of chronic administration of pentobarbital on activity of adenylate cyclase (AC) and protein kinase C (PKC) in the rat brain by autoradiography. Recently, it has been suggested that the phosphorylation of specific proteins may be involved in the development of physical dependence. An experimental model of barbiturate tolerance and dependence was developed using i.c.v. infusion of pentobarbital (300 μg/ 10 μl/hr for 7 days) by osmotic minipumps and abrupt withdrawal from pentobarbital. The levels of [^3H]forskolin binding were elevated (28–67%) in cortex, thalamus, dentate gyrus, hippocampal CA3 and cerebellum of the pentobarbital withdrawal animals, while these changes were not observed in tolerant rats. The levels of [^3H]Phorbol Dibutyrate binding were highly elevated (38–65%) in the region of cortex, caudate putamen, septum, thalamus, dentate gyrus, and cerebellum of rats withdrawal from pentobarbital. These results show that the levels of AC and PKC were significantly elevated in pentobarbital withdrawal rats, and suggest that the levels of AC and PKC are altered in a region-specific manner during pentobarbital withdrawal.
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changes in 3h forskolin binding to adenylate cyclase and 3h Phorbol Dibutyrate binding to protein kinase c in pentobarbital tolerant dependent rats
Neurochemical Research, 1998Co-Authors: Susan E. WellmanAbstract:These studies were designed to examine the effect of chronic administration of pentobarbital on activity of adenylate cyclase (AC) and protein kinase C (PKC) in the rat brain by autoradiography. Recently, it has been suggested that the phosphorylation of specific proteins may be involved in the development of physical dependence. An experimental model of barbiturate tolerance and dependence was developed using i.c.v. infusion of pentobarbital (300 μg/ 10 μl/hr for 7 days) by osmotic minipumps and abrupt withdrawal from pentobarbital. The levels of [3H]forskolin binding were elevated (28–67%) in cortex, thalamus, dentate gyrus, hippocampal CA3 and cerebellum of the pentobarbital withdrawal animals, while these changes were not observed in tolerant rats. The levels of [3H]Phorbol Dibutyrate binding were highly elevated (38–65%) in the region of cortex, caudate putamen, septum, thalamus, dentate gyrus, and cerebellum of rats withdrawal from pentobarbital. These results show that the levels of AC and PKC were significantly elevated in pentobarbital withdrawal rats, and suggest that the levels of AC and PKC are altered in a region-specific manner during pentobarbital withdrawal.
Yoh Takuwa - One of the best experts on this subject based on the ideXlab platform.
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Activators of protein kinase C induce p34cdc2 histone H1 kinase stimulation in Swiss 3T3 fibroblasts.
Biochemical and biophysical research communications, 1992Co-Authors: Noriko Takuwa, Wei Zhou, Mamoru Kumada, Yoh TakuwaAbstract:Abstract Phorbol-12,13-Dibutyrate and 1,2-dioctanoylglycerol, activators of protein kinase C (PKC) that stimulate DNA synthesis in serum-deprived Swiss 3T3 fibroblasts, induce histone H1 kinase activity associated with anti-cdc2 immunoprecipitates after a lag period of 15h, a time point close to G 1 S boundary of the cell cycle in these cells. Downregulation of PKC does not affect the basal cdc2 kinase activity, but potently inhibits both Phorbol Dibutyrate- and dioctanoylglycerol-induced cdc2 kinase activation. Phorbol Dibutyrate induces a dramatic increase in the p34cdc2 protein level as well as the appearance of p35-p36 forms of cdc2 on Western blot. In PKC-downregulated cells, the p34 form of cdc2 remains elevated but p35-p36 forms do not appear upon Phorbol Dibutyrate stimulation. These results demonstrate that PKC activation leads to cdc2 kinase activation in mitogenically responsive Swiss 3T3 cells, and strongly suggest that both expression of p34cdc2 protein and its posttranslational modification(s) are involved in this process. Western blot analysis of PKC isozymes suggests that either PKCα, PKCδ or PKCe may be involved in p34cdc2 kinase activation and mitogenesis.
Robert S. Moreland - One of the best experts on this subject based on the ideXlab platform.
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Partial bladder outlet obstruction selectively abolishes protein kinase C induced contraction of rabbit detrusor smooth muscle.
The Journal of urology, 2006Co-Authors: Michaela C. Stanton, J. Christopher Austin, Daniel P. Delaney, Alex Gosfield, James O. Marx, Stephen A. Zderic, Samuel Chacko, Robert S. MorelandAbstract:Despite the acute onset, partial bladder outlet obstruction in the rabbit induces detrusor remodeling similar to that in men with benign prostatic hyperplasia in terms of its impact on structural and functional alterations in smooth muscle. We determined if partial bladder outlet obstruction induced remodeling alters the protein kinase C signaling pathway that leads to contraction. Smooth muscle from control animals and those subjected to 2 weeks of partial bladder outlet obstruction were mounted for isometric force recording, measurement of myosin light chain phosphorylation and levels of adducin phosphorylation. Bladder muscle strips were stimulated by Phorbol Dibutyrate or carbachol in the presence and absence of bisindolylmaleimide-1. Smooth muscle strips from animals subjected to partial bladder outlet obstruction showed little to no increase in stress in response to Phorbol Dibutyrate and no increase in myosin light chain phosphorylation levels. Muscle strips from control animals produced a robust contraction with concomitant increases in myosin light chain phosphorylation. Inhibition of protein kinase C by bisindolylmaleimide-1 significantly depressed carbachol induced contractions of muscle strips from control animals but it had no effect on carbachol induced contractions of muscle strips from outlet obstructed animals. Phorbol Dibutyrate increased phospho-adducin levels in muscle strips from the 2 animal sources, suggesting that protein kinase C could be activated. We propose that partial bladder outlet obstruction does not alter protein kinase C activation, but rather abolishes or uncouples the pathway(s) downstream of protein kinase C, leading to contraction. Loss of this pathway may contribute to the loss of normal voiding behavior and the resultant decompensated state.
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Partial bladder outlet obstruction selectively abolishes protein kinase C induced contraction of rabbit detrusor smooth muscle.
Journal of Urology, 2006Co-Authors: Michaela C. Stanton, J. Christopher Austin, Daniel P. Delaney, Alex Gosfield, James O. Marx, Stephen A. Zderic, Samuel Chacko, Robert S. MorelandAbstract:Purpose: Despite the acute onset, partial bladder outlet obstruction in the rabbit induces detrusor remodeling similar to that in men with benign prostatic hyperplasia in terms of its impact on structural and functional alterations in smooth muscle. We determined if partial bladder outlet obstruction induced remodeling alters the protein kinase C signaling pathway that leads to contraction.Materials and Methods: Smooth muscle from control animals and those subjected to 2 weeks of partial bladder outlet obstruction were mounted for isometric force recording, measurement of myosin light chain phosphorylation and levels of adducin phosphorylation. Bladder muscle strips were stimulated by Phorbol Dibutyrate or carbachol in the presence and absence of bisindolylmaleimide-1.Results: Smooth muscle strips from animals subjected to partial bladder outlet obstruction showed little to no increase in stress in response to Phorbol Dibutyrate and no increase in myosin light chain phosphorylation levels. Muscle strips f...
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Cyclic AMP and cyclic GMP relax Phorbol ester-induced contractions of rat aorta by different mechanisms
Life sciences, 1997Co-Authors: Hee Yul Ahn, Ki Churl Chang, Myung Hee Chung, Myung-suk Kim, Robert S. MorelandAbstract:Abstract This study was designed to test the hypothesis that 8-Br-cAMP and 8-Br-cGMP dependent relaxation of Phorbol Dibutyrate stimulated contractions of intact rat aorta are independent of changes in the level of myosin light chain phosphorylation. Phorbol Dibutyrate stimulated contraction with a concomitant increase in myosin light chain phosphorylation in normal tissues and without an increase in myosin light chain phosphorylation in calcium-depleted tissues. Phorbol Dibutyrate stimulated contractions in normal CaCl2-containing physiological salt solution were relaxed in a concentration-dependent manner by 8-Br-cAMP and 8-Br-cGMP. Phorbol Dibutyrate-induced contractions in the absence of Ca2+ were only relaxed by 8-Br-cGMP; 8-Br-cAMP had no effect The relaxation induced by 8-Br-cGMP was associated with a decrease in myosin light chain phosphorylation suggesting that cGMP-dependent protein kinase may alter the activity of either the myosin light chain kinase or phosphatase. The relaxation induced by 8-Br-cAMP was not associated with a decrease in phosphorylation suggesting that cAMP-dependent protein kinase may uncouple myosin light chain phosphorylation from force.
Kate Bárány - One of the best experts on this subject based on the ideXlab platform.
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Protein phosphorylation during the contraction-relaxation-contraction cycle of arterial smooth muscle.
Archives of biochemistry and biophysics, 1992Co-Authors: Michael Barany, Erzsébet Polyák, Kate BárányAbstract:Abstract Porcine carotid arterial muscles were labeled with 32P and then subjected to a resting-contraction-relaxationcontraction cycle. Four different agents were used for contraction: KCl, histamine, norepinephrine, and Phorbol Dibutyrate. To relax the contracted muscles, they were washed with physiological salt solution. Changes in the [32P]phosphate content of four different proteins—myosin light chain, a 28-kDa cytosolic protein, desmin, and caldesmon—were followed. In a short contractionrelaxation-contraction cycle lasting minutes, induced by K+, histamine, or norepinephrine, only the light chain underwent a phosphorylation-dephosphorylation-rephosphorylation without concomitant cyclic phosphorylation of the 28-kDa protein, desmin, or caldesmon. In a contraction-relaxation-contraction cycle of long duration, 60-min contractions with K+, histamine, or norepinephrine, cyclic phosphorylation of both the light chain and desmin was observed. With 60-min Phorbol Dibutyrate stimulation, in the long contraction-relaxation-contraction cycle, the phosphorylations of the light chain, desmin, and caldesmon were cycling. It is concluded that under physiological conditions, light-chain phosphorylation initiates both short and sustained arterial contraction. Desmin phosphorylation is likely to be involved in force maintenance during sustained contraction.
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Protein phosphorylation in arterial muscle contracted by high concentration of Phorbol Dibutyrate in the presence and absence of Ca2
Biochimica et biophysica acta, 1992Co-Authors: Kate Bárány, Erzsébet Polyák, Michael BaranyAbstract:Abstract Porcine carotid arterial muscles were 32 P-labeled then contracted with 8 μM Phorbol Dibutyrate (PDBu) in normal physiological salt solution (PSS) and in Ca 2+ -free PSS containing 0.5 mM ethyene glycol-bis (β-aminoethyl ether)- N,N,N′,N′ -tetraacetate. Significant incorporation of [ 32 P]phosphate into the 20-kDa myosin light chain, a 28-kDa protein, desmin and caldesmon was measured with no apparent difference between normal and Ca 2+ -depleted muscles. Ca-determination showed that the Ca 2+ -depleted muscle contained 15% of the total Ca of the normal muscle. However, determination of the actin-bound Ca revealed that all the Ca in the Ca 2+ -depleted muscle could be accounted for by its actin-bound Ca. Accordingly, protein phosphorylation during the slow PDBu-induced contraction may proceed in the virtual absence of free Ca 2+ . Phosphopeptide mapping of the myosin light chain isolated from muscles contracted with PDBu either in the presence or absence of Ca 2+ showed that two-thirds of the incorporated [ 32 P]phosphate was attributable to myosin light chain kinase catalyzed phosphorylation and one-third was due to phosphorylation by protein kinase C. PDBu increased the phosphorylation of the 28-kDa protein, desmin and caldesmon two- to threefold, as compared with that in muscles contracted by KCl depolarization or by the receptor mediated agonists norepinephrine and histamine. Muscles contracted by high concentration of PDBu in the presence or absence of Ca 2+ could be fully relaxed and recontracted.
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Modification of myosin light chain phosphorylation in sustained arterial muscle contraction by Phorbol Dibutyrate.
Biochimica et biophysica acta, 1991Co-Authors: Anikó Rokolya, Michael Barany, Kate BárányAbstract:The decrease in phosphorylation of the 20 kDa myosin light chain during prolonged K + -stimulation of arterial smooth muscle was counteracted by treating this muscle with Phorbol Dibutyrate. Quantitative phosphopeptide analysis revealed that Phorbol Dibutyrate induced phosphorylation of serine and threonine residues in the light chain by protein kinase C and phosphorylation of a threonine residue by myosin light chain kinase. The same residues of light chain were also phosphorylated when Phorbol Dibutyrate was added to muscles pretreated either with the Ca 2+ -channel-blocking agents nifedipine and verapamil, or with the Ca 2+ -chelating agent ethylene glyco-bis(β-aminoethyl ether)- N,N,N′,N′ -tetraacetic acid. The results indicate an interrelationship between protein kinase C and myosin light chain kinase phosphorylated sites of light chain in intact arterial smooth muscle.
Michael C Venuti - One of the best experts on this subject based on the ideXlab platform.
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synthesis and biological activity of a 5 6 substituted teleocidin
Bioorganic & Medicinal Chemistry Letters, 1992Co-Authors: Rob Webb, Michael C VenutiAbstract:Abstract The synthesis of 5,6-substituted teleocidin analogue 3 is reported. Reduction of oxime 7 (obtained from indole 6 ) gave diastereomeric amines 8 and 9 which were cyclized to give esters 10 and 11 , respectively. Reduction of 10 yielded teleocidin analogue 3 , which displayed activity comparable to (−)-indolactam V in a standard 3 [H]-Phorbol-Dibutyrate binding assay.