Activation of protein kinase C by short chain phosphatidylcholines.

Walker, J M; Sando, Julianne J.

doi:10.1016/s0021-9258(18)68816-7

Cited by 52 publications

(11 citation statements)

References 28 publications

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“…We speculate that PKC activation at domain interfaces may share features with activation by short-chain PC micelles (Walker et al, 1990;Walker & Sando, 1988), by highly unsaturated phospholipids (Bolen & Sando, 1992) in the presence of DO, and by branched-chain analogues of distearin (DS) with bulky derivatives (Zhou et al, 1988). Short-chain PC micelles have a spacing between the lipid components more similar to a monolayer in the liquidextended phase than to a bilayer (McConnell, 1991).…”

Section: Discussionmentioning

confidence: 99%

Activation of Protein Kinase C by Coexisting Diacylglycerol-Enriched and Diacylglycerol-Poor Lipid Domains

et al. 1997

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To test the hypothesis that activation of protein kinase C (PKC) is related to the interface between coexisting diacylglycerol- (DAG-) enriched and DAG-poor phases, the thermotropic phase behavior of the ternary mixtures dimyristoylphosphatidylcholine (DMPC)/dimyristoylphosphatidylserine (DMPS)/dioleoylglycerol (DO), DMPC/DMPS/1-palmitoyl-2-oleoylglycerol (PO), and DMPC/DMPS/dimyristoylglycerol (DM) was analyzed and compared with the ability of the lipid mixtures to support PKC activity. Differential scanning calorimetry (DSC) was used to monitor the gel-to-liquid crystalline phase transition as a function of the mole fraction of DO (chiDO), PO (chiPO), or DM (chiDM) in DMPC/DMPS (1:1) multilamellar vesicles (MLVs) and of chiDO in large unilamellar vesicles (LUVs). The addition of DAG at low mole fractions gave rise to the appearance of two or more overlapping transitions. The phase boundaries of the ternary mixtures deduced from the partial phase diagrams were chiDO = approximately 0.10 and approximately 0.3 for DMPC/DMPS/DO, chiPO = approximately 0.05 and approximately 0.4 for DMPC/DMPS/PO, and chiDM = approximately 0.025 and approximately 0.5-0.6 for DMPC/ DMPS/DM. Above these mole fractions of DAG, the transitions again became very sharp. The ability of the lipid mixtures to support activity of PKC alpha and PKC eta was examined below and above the gel-to-liquid crystalline phase transition. In the gel phase, PKC activity went through a maximum as a function of increasing mole fraction of each DAG and was restricted to lipid compositions in which coexisting phases were observed. Maximal activity decreased with increasing saturation of the DAG. In the fluid state, maximal PKC activity was shifted to higher DO mole fractions and the peak was much broader. Collectively, these data support a role for both the presence and nature of interface between compositionally distinct domains in activation of PKC.

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Section: Discussionmentioning

confidence: 99%

Activation of Protein Kinase C by Coexisting Diacylglycerol-Enriched and Diacylglycerol-Poor Lipid Domains

et al. 1997

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“…This mechanism for PKC-membrane binding does not involve Ca2+ but still features a charge interaction at the membrane surface. We have shown, however, that PC micelles, which do not bind Ca2+, can activate PKC in the absence of acidic phospholipids (Walker & Sando, 1988;Walker et al, 1990). Therefore, depending on the physical state of the lipid, charge interactions are not strictly required for activation.…”

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confidence: 90%

Effect of phospholipid unsaturation on protein kinase C activation

Bolen¹,

Sando²

1992

Biochemistry

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To examine the hypothesis that physical features of the membrane contribute to protein kinase C activation, phosphatidylcholine/phosphatidylserine/diolein (70:25:5) vesicles of defined acyl chain composition were tested for their ability to activate the enzyme. Maximal activation was found to correlate with the mole percent unsaturation in the system. Unsaturation could be provided by either the phosphatidylserine or the phosphatidylcholine component. Vesicles containing 5 mol% diolein but lacking any unsaturation in the phospholipid did not support activity, indicating that acidic head groups alone are not sufficient for activity. The saturated lipid vesicles could be rendered effective but only at very high (25 mol%) concentrations of diolein. The degree of acyl chain unsaturation and the positioning of the double bond had little effect on the activity, suggesting that the effect of the unsaturation is due to some physical property of the lipid rather than to a specific lipid-protein interaction. Addition of cholesterol to both saturated and unsaturated systems indicated that fluidity, as assessed by fluorescence anisotropy, did not correlate with activity. These results suggest that a physical property of the membrane other than fluidity is important for the activation of protein kinase C. A model for protein kinase C activation involving phase separation and/or head group spacing is discussed.

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“…A mixed isozyme preparation of PKC, partially purified from rat brain, was generously supplied by Ms. Muriel C. Maurer and Dr. Julianne J. Sando (Department of Pharmacology, University of Virginia, Charlottesville, VA). The PKC preparation was purified using DE-52 cellulose and threonine Sepharose chromatography (Kikkawa, Go, Koumoto, and Nishizuka, 1986;Walker and Sando, 1988). For experiments using internal cellular dialysis, a solution of either CS or PKC was included in the internal pipette solution as described previously (Walsh et al, 1989;Walsh, 1991).…”

Section: Preparation Of Drugs and Dialysis Of Cells With Protein Kinasesmentioning

confidence: 99%

Inhibition of heart calcium and chloride currents by sodium iodide. Specific attenuation in cAMP-dependent protein kinase-mediated regulation.

Walsh

Long

1992

The Journal of General Physiology

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The enzymes cAMP-dependent protein kinase (PKA) and protein kinase C (PKC) regulate the activity of cardiac ion channel proteins. In this study the whole-cell arrangement of the patch clamp technique was used to examine the effect of NaI on PKA-stimulated CI-and Ca 2+ channels in isolated guinea pig ventricular myocytes. CI-currents (lcl) activated either by the 13-adrenergic agonist isoproterenol or the membrane-soluble cAMP analogue, 8-chlorphenylthio (8-CPT) cAMP, were greatly reduced in amplitude after substitution of an external solution containing 140 mM NaCI with a solution containing 140 mM NaI. This reduction was accompanied by a shift of -7 mV in the reversal potential (E,~) for Icl and could be reversed upon return to the NaCI external solution. Inhibition of Io by NaI occurred in a concentration-dependent manner and was more pronounced for inward Io (ICs0 = 19 mM at -60 mV) than for outward Ict (ICs0 = 60 mM at +60 mV). In contrast to Icl activated by PKA, lcl activated by PKC was slightly augmented in the presence of NaI and the E,~v was found to shift by -15 mV. Based on these data, the relative permeability of I-to C1-(Pl/Pcl) for this channel was calculated to be 1.79. NaI produced no change in the amplitude of inward calcium currents (/ca) recorded under basal conditions, but strongly inhibited/ca augmented by isoproterenol and 8-CPT cAMP, and during dialysis of cells with the catalytic subunit of PKA (CS). The in vitro incorporation of [~/-s2P]ATP into histone IIA and Kemptide, measured in the presence of PKA and cAMP, was not significantly different in assay mixtures containing salts of CI-and I-. However, the ability of isoproterenol to augment basal/ca in whole-cell experiments was attenuated when experiments were carried out entirely in NaI external solution. Thus, the reduction in Io and lca observed in this study may result from a direct effect of I-on the phosphorylation/ dephosphorylation of cardiac ion channel proteins or associated regulatory proteins.Address reprint requests to Dr.

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Activation of protein kinase C by short chain phosphatidylcholines.

Cited by 52 publications

References 28 publications

Activation of Protein Kinase C by Coexisting Diacylglycerol-Enriched and Diacylglycerol-Poor Lipid Domains

Activation of Protein Kinase C by Coexisting Diacylglycerol-Enriched and Diacylglycerol-Poor Lipid Domains

Effect of phospholipid unsaturation on protein kinase C activation

Inhibition of heart calcium and chloride currents by sodium iodide. Specific attenuation in cAMP-dependent protein kinase-mediated regulation.

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