The relationship between the bilayer to hexagonal phase transition temperature in membranes and protein kinase C activity

1988 ◽  
Vol 8 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Richard M. Epand ◽  
Alan R. Stafford ◽  
James J. Cheetham ◽  
Remo Bottega ◽  
Eric H. Ball
Keyword(s):  
Phase Transition ◽  
Protein Kinase C ◽  
Transition Temperature ◽  
Protein Kinase ◽  
Phase Transition Temperature ◽  
Hexagonal Phase ◽  
Protein Kinase C Inhibitors ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Protein Kinase C Activators

A number of substances affect the activity of protein kinase C. Among uncharged and zwitterionic compounds, those which activate protein kinase C also lower the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine while substances which inhibit protein kinase C raise this transition temperature. Using this criteria, we have identified 3β-chloro-5-cholestene, 5β-cholan-24-ol and eicosane as new protein kinase C activators and have shown that Z-Ser-Leu-NH2, Z-Gly-Leu-NH2, Z-Tyr-Leu-NH2, cyclosporin A and cholestan-3β, 5α, 6β-triol are protein kinase C inhibitors.

Evidence for the regulation of the activity of protein kinase C through changes in membrane properties

1991 ◽  
Vol 11 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Richard M. Epand ◽  
Raquel F. Epand ◽  
Bryan T.-C. Leon ◽  
Fredric M. Menger ◽  
J. F. Kuo
Keyword(s):  
Phase Transition ◽  
Protein Kinase C ◽  
Transition Temperature ◽  
Protein Kinase ◽  
Phase Transition Temperature ◽  
Hexagonal Phase ◽  
Lipid Phase ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Lipid Polymorphism

We measured the effects of two branched-chain analogs of distearoyl-phosphatidylcholine, containing either a methyl or an n-butyl group at the 8 position, on the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine. The former compound raised the bilayer to hexagonal phase transition temperature while the latter compound lowered it. The opposite effects of these amphiphiles on protein kinase C activity (inhibition and activation, respectively) correlated with their effects on lipid polymorphism. Because of the similarity of the structures of these two compounds, it seems likely that their opposite effects on the activity of protein kinase C is a result of their alteration of the lipid environment of the membrane rather than to binding to a specific site on the protein. We also compared the effects of hexachlorophene on lipid polymorphism and protein kinase C activity at high and at low calcium concentrations. We also found that the effect of hexachlorophene forming a complex with Ca2+ is to increase both the hexagonal phase forming propensity of the membrane as well as to increase the activity of protein kinase C, again demonstrating the correlation between lipid phase propensity and effects on protein kinase C activity.

Protein kinase C and progesterone-induced maturation in Xenopus oocytes

Development ◽  
1990 ◽  
Vol 109 (3) ◽  
pp. 597-604
Author(s):  
R.L. Varnold ◽  
L.D. Smith
Keyword(s):  
Cell Cycle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Xenopus Oocytes ◽  
Plasma Membranes ◽  
Protein Kinase C Inhibitors ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Concomitant Reduction ◽  
Dependent Protein

Though progesterone-induced maturation has been studied extensively in Xenopus oocytes, the mechanism whereby the prophase block arrest is released is not well understood. The current hypothesis suggests that a reduction in cAMP and subsequent inactivation of cAMP-dependent protein kinase is responsible for reentry into the cell cycle. However, several lines of evidence indicate that maturation can be induced without a concomitant reduction in cAMP. We show that the mass of diacylglycerol in whole oocytes and plasma membranes decreases 29% and 10% respectively, within the first 15 sec after the addition of progesterone. Diacylglycerol in plasma membranes further decreased 59% by 5 min. We also show that the protein kinase C inhibitors sphingosine and staurosporine can induce oocyte maturation. In addition, the synthetic diglyceride, DiC8, and microinjected PKC can inhibit or delay progesterone-induced maturation. These results together suggest that a transient decrease in protein kinase C activity may regulate entry into the cell cycle. The mechanism whereby DAG is decreased in response to progesterone is unclear. Initial studies show that progesterone leads to a decrease in IP3 suggesting that progesterone may act by reducing the hydrolysis of PIP2. On the other hand, progesterone caused a decrease in the amount of [3H]arachidonate labelling in DAG during the same time suggesting that progesterone may stimulate lipase activity. The relationship between postulated changes in the PKC pathway and those hypothesized for the PKA pathway are discussed.

Trypsin stimulation of aldosterone and 18-hydroxycorticosterone production by rat adrenal zona glomerulosa tissue is mediated by activation of protein kinase C

1990 ◽  
Vol 5 (1) ◽  
pp. 85-93 ◽  
Author(s):  
G. P. Vinson ◽  
S. M. Laird ◽  
J. P. Hinson ◽  
N. Mallick ◽  
S. Marsigliante ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase C ◽  
Polymyxin B ◽  
Zona Glomerulosa ◽  
Protein Kinase C Inhibitors ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Tissue Sensitivity ◽  
Protein Components

ABSTRACT When rat adrenal whole capsules, containing the zona glomerulosa, were incubated, addition of the protein kinase C inhibitors TMB-8 (10 μmol/l), W7, H7, polymyxin-B and sphingosine (all 1 μmol/l) was found to inhibit the steroidogenic response to trypsin. Aldosterone and 18-hydroxycorticosterone were strongly, and corticosterone moderately, affected, while the production of 18-hydroxydeoxycorticosterone was neither stimulated by trypsin nor inhibited by the protein kinase C inhibitors. Addition of neomycin, which prevents substrate interaction with phospholipase C, also inhibited the response to trypsin, while addition of phospholipase C itself stimulated aldosterone, 18-hydroxycorticosterone and corticosterone production with the same tissue sensitivity as trypsin. Addition of phospholipase A2 had no effect. Direct assay of protein kinase C activity showed that trypsin stimulation effected the translocation of Ca2+/phospholipid-activated protein kinase C from the cytosolic to the membrane fraction. When glomerulosa tissue was incubated with [32P]ATP, and cytosolic proteins were subjected to isoelectric focusing on polyacrylimide gels, autoradiography showed that incorporation of 32P into several protein components was increased by trypsin stimulation. It was concluded that trypsin exerts its stimulatory effects on steroidogenesis by activating protein kinase C; not, however, by generating the Ca2+/phospholipid-independent fragment, but possibly by enhancing the activity of phospholipase C.

scholarly journals Lycopene depresses glutamate release through inhibition of voltage-dependent Ca2+ entry and protein kinase C in rat cerebrocortical nerve terminals

2018 ◽  
Vol 96 (5) ◽  
pp. 479-484 ◽  
Author(s):  
Cheng-Wei Lu ◽  
Chi-Feng Hung ◽  
Wei-Horng Jean ◽  
Tzu-Yu Lin ◽  
Shu-Kuei Huang ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Glutamate Release ◽  
Inhibitory Effect ◽  
Nerve Terminals ◽  
Protein Kinase C Inhibitors ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Voltage Dependent ◽  
Intracellular Ca

Lycopene is a natural dietary carotenoid that was reported to exhibit a neuroprotective profile. Considering that excitotoxicity and cell death induced by glutamate are involved in many brain disorders, the effect of lycopene on glutamate release in rat cerebrocortical nerve terminals and the possible mechanism involved in such effect was investigated. We observed here that lycopene inhibited 4-aminopyridine (4-AP)-evoked glutamate release and intrasynaptosomal Ca2+ concentration elevation. The inhibitory effect of lycopene on 4-AP-evoked glutamate release was markedly reduced in the presence of the Cav2.2 (N-type) and Cav2.1 (P/Q-type) channel blocker ω-conotoxin MVIIC, but was insensitive to the intracellular Ca2+-release inhibitors dantrolene and CGP37157. Furthermore, in the presence of the protein kinase C inhibitors GF109203X and Go6976, the action of lycopene on evoked glutamate release was prevented. These results are the first to suggest that lycopene inhibits glutamate release from rat cortical synaptosomes by suppressing presynaptic Ca2+ entry and protein kinase C activity.

Protein kinase C activity does not mediate the inhibitory effect of carbachol on chloride secretion by T84 cells

1994 ◽  
Vol 267 (5) ◽  
pp. C1224-C1230 ◽  
Author(s):  
A. E. Traynor-Kaplan ◽  
T. Buranawuti ◽  
M. Vajanaphanich ◽  
K. E. Barrett
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chloride Secretion ◽  
Inhibitory Effect ◽  
T84 Cells ◽  
Calcium Dependent ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Protein Kinase C Activators ◽  
Inositol Tetrakisphosphate

Carbachol induces calcium-dependent chloride secretion and activates protein kinase C in T84 cells. However, prolonged stimulation with carbachol or direct activation of protein kinase C inhibits subsequent calcium-dependent chloride secretion. Furthermore, the ability of carbachol to elevate inositol tetrakisphosphate levels may be linked to inhibition of chloride secretion. Here we demonstrate that protein kinase C activation increases levels of inositol tetrakisphosphates (1,3,4,6- and 3,4,5,6-isomers) in T84 colonic epithelia. Furthermore, this corresponds to an inhibition of chloride secretion. However, protein kinase C is unlikely to mediate the analogous effects of carbachol. Neither the ability of carbachol to inhibit calcium-dependent chloride secretion nor its effects on inositol 3,4,5,6-tetrakisphosphate levels were reversed by staurosporine. Carbachol also has quantitatively and qualitatively different effects on inositol tetrakisphosphate isomers than protein kinase C activators. Thus protein kinase C activity can increase levels of various inositol tetrakisphosphate isomers within T84 cells but does not mediate carbachol-induced increases in these putative messengers. These data further support the hypothesis that inositol 3,4,5,6-tetrakisphosphate is a negative second messenger, uncoupling epithelial chloride secretion from changes in intracellular calcium.

Response of aequorin-loaded platelets to activators of protein kinase C

1989 ◽  
Vol 256 (1) ◽  
pp. C35-C43 ◽  
Author(s):  
J. A. Ware ◽  
M. Saitoh ◽  
M. Smith ◽  
P. C. Johnson ◽  
E. W. Salzman
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Platelet Response ◽  
Free System ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Protein Kinase C Activators ◽  
Protein Kinase C Inhibitor ◽  
A Cell ◽  
Induced Aggregation

The protein kinase C activators phorbol ester 12-myristate 13-acetate (PMA) and 1-oleyl-2-acetylglycerol (DAG) cause platelet aggregation, secretion, and a rise in aequorin-indicated cytoplasmic Ca2+ ([Ca2+]i), but the importance of this action to platelet activation by these agonists has not been established. We found that the previous addition of PMA or DAG either enhanced or inhibited the platelet response if thrombin was subsequently added, depending on the latter's concentration. The effects of PMA or DAG on the response to thrombin were obtained only if the agonists were added in concentrations sufficient to elevate [Ca2+]i themselves. A [Ca2+]i rise also occurred after the second agonist (thrombin), but its magnitude did not necessarily correlate with subsequent aggregation, secretion, or the activation of protein kinase C as reported by the phosphorylation of a 47-kDa protein (p47). The protein kinase C inhibitor sphingosine inhibited aggregation and p47 phosphorylation caused by PMA or DAG alone or with thrombin, but the [Ca2+]i rise in response to the first agonist was not affected. PMA-induced aggregation and p47 phosphorylation were inhibited by quin2, which also inhibited protein kinase C activity in a cell-free system. We conclude that a rise in aequorin-indicated [Ca2+]i is necessary for PMA or DAG to activate platelets or to alter the subsequent platelet response to thrombin; this [Ca2+]i rise may be a prerequisite for activation of protein kinase C.

Chronic treatment by the calcium channel blocker ± PN 200-110 in the rat counteracts the stimulations of pituitary weight, prolactin release and pituitary C-kinase activity induced by a chronic estradiol treatment, in vivo

1990 ◽  
Vol 122 (3) ◽  
pp. 403-408
Author(s):  
Ph. Touraine ◽  
P. Birman ◽  
F. Bai-Grenier ◽  
C. Dubray ◽  
F. Peillon ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Channel Blocker ◽  
Plasma Prolactin ◽  
Estradiol Treatment ◽  
Kinase C ◽  
Protein Kinase C Activity

Abstract In order to investigate whether a calcium channel blocker could modulate the protein kinase C activity in normal and estradiol pretreated rat pituitary, female Wistar rats were treated or not (controls) with ± PN 200-110 (3 mg · kg−1 · day−1, sc) for 8 days or with estradiol cervical implants for 8 or 15 days, alone or in combination with PN 200-110 the last 8 days. Estradiol treatment induced a significant increase in plasma prolactin levels and pituitary weight. PN 200-110 administered to normal rats did not modify these parameters, whereas it reduced the effects of the 15 days estradiol treatment on prolactin levels (53.1 ± 4.9 vs 95.0 ±9.1 μg/l, p<0.0001) and pituitary weight (19.9 ± 0.4 vs 23.0 ± 0.6 mg, p <0.001), to values statistically comparable to those measured after 8 days of estradiol treatment. PN 200-110 alone did not induce any change in protein kinase C activity as compared with controls. In contrast, PN 200-110 treatment significantly counteracted the large increase in soluble activity and the decrease in the particulate one induced by estradiol between day 8 and day 15. We conclude that PN 200-110 opposed the stimulatory effects of chronic in vivo estradiol treatment on plasma prolactin levels and pituitary weight and that this regulation was related to a concomitant modulation of the protein kinase C activity.

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