Enhancement of calcium current in Aplysia neurones by phorbol ester and protein kinase C

  title={Enhancement of calcium current in Aplysia neurones by phorbol ester and protein kinase C},
  author={S. A. DeRiemer and James Strong and Katherine A. Albert and Paul Greengard and L. K. Kaczmarek},
One of the molecular mechanisms capable of regulating the physiological properties of neurones is the phosphorylation of ion channels and other cellular components by cyclic AMP-dependent protein kinase1. Another protein kinase present in high concentrations in the mammalian brain is protein kinase C (a calcium/phosphatidylserine/diacylglycerol-dependent protein kinase)2–5, but there is no direct evidence, as yet, for the involvement of this enzyme in the control of neuronal excitability. We… 
Phorbol esters block a voltage-sensitive chloride current in hippocampal pyramidal cells
It is reported that hippocampal pyramidal cells contain a previously undescribed voltage-dependent chloride current which is active at resting potential and is turned off either by membrane depolarization or by activation of protein kinase C by phorbol esters, and it is proposed that this current may reside predominantly in the cell's dendritic membrane and thereby may regulate dendedritic excitability.
Phorbol esters, protein phosphorylation and the regulation of neuronal ion channels.
  • L. Kaczmarek
  • Biology, Computer Science
    The Journal of experimental biology
  • 1986
Exposure of isolated bag cell neurones to activators of protein kinase C results in the enhancement of their action potentials through an increase in the amplitude of their voltage-dependent calcium current.
  • M. Klee
  • Biology
    Journal of basic and clinical physiology and pharmacology
  • 1990
Some transmitters are known to activate protein kinases leading to phosphorylation: protein kinase C which is found in neuronal tissue of vertebrates and invertebrates can be activated by phorbol esters, which can increase the amplitude and the slope of the rising phase of the action potential.
Inhibitors of protein kinase C prevent enhancement of calcium current and action potentials in peptidergic neurons of Aplysia
It is reported that another PKC inhibitor, sphinganine, also inhibits the effect of TPA on action potential height and calcium current in cultured bag cell neurons, and that N-acetylsphinga, an inactive sphinga analog, fails to inhibit the effects of PKC activators.
A diacylglycerol analogue reduces neuronal calcium currents independently of protein kinase C activation
Micromolar levels of OAG and phorbol esters depress Ca2+ currents in chick sensory neurons independently of their effect as activators of protein kinase C, indicating that their site of action is on the outside of the membrane.
Forskolin and phorbol esters reduce the same potassium conductance of mouse neurons in culture.
Neither forskolin (FOR) nor phorbol 12,13-dibutyrate (PDBu) altered resting membrane properties but both increased the duration of calcium-dependent action potentials in both central and peripheral neurons, suggesting that two independent second messenger systems may affect the same potassium conductance.
Stimulation of protein kinase C recruits covert calcium channels in Aplysia bag cell neurons
It is reported that enhancement of calcium current in the peptidergic bag cell neurons of Aplysia by protein kinase C occurs through a different mechanism, the recruitment of a previously covert class of calcium channel.


Modulation of potassium current kinetics in bag cell neurons of Aplysia by an activator of adenylate cyclase
  • J. Strong
  • Biology
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1984
A voltage clamp study of bag cells in primary culture was undertaken in order to characterize the effects of cAMP on the cells' electrical properties and it is suggested that changes in the A-current could explain the ability of the bag cells to fire repetitively during the afterdischarge.
A voltage-clamp analysis of currents underlying cyclic AMP-induced membrane modulation in isolated peptidergic neurons of Aplysia.
A two-electrode voltage clamp is used to study the properties of isolated bag cell neurons in cell culture and their response to 8 benzylthio-cAMP (8 BTcAMP) and N6-n-butyl 8BTcAMP, distinguished by their differing pharmacological and voltage-activation properties.
Calcium-dependent protein kinase: widespread occurrence in various tissues and phyla of the animal kingdom and comparison of effects of phospholipid, calmodulin, and trifluoperazine.
  • J. Kuo, R. Andersson, R. W. Wrenn
  • Biology, Chemistry
    Proceedings of the National Academy of Sciences of the United States of America
  • 1980
It is suggested that phospholipid-sensitive Ca2-dependent protein kinase may mediate certain actions of Ca2+ in tissues, acting independently or in a complementary manner with other protein phosphorylation systems stimulated by calmodulin-Ca2+, cyclic AMP, or cyclic GMP.
The role of protein kinase C in cell surface signal transduction and tumour promotion
Protein kinase C probably serves as a receptor for the tumour promoters and further exploration of the roles of this enzyme may provide clues for understanding the mechanism of cell growth and differentiation.
Neurotransmitter modulation, phosphodiesterase inhibitor effects, and cyclic AMP correlates of afterdischarge in peptidergic neurites.
The data suggest that serotonin and/or dopamine may control bag cell activity and that activation of adenylate cyclase is linked to bag cell afterdischarge.
T-cell mitogens cause early changes in cytoplasmic free Ca2+ and membrane potential in lymphocytes
It is shown here that lectins known to stimulate T cells raise average [Ca2+]1 approximately twofold within a few minutes, and the co-carcinogen 12-0-tetradecanoylphorbol-13-acetate (TPA) seems to stimulate cell functions normally activated by Ca2+.
The expression of long lasting afterdischarge by isolated Aplysia bag cell neurons
The response of cultured bag cells to the CAMP analogue, 8-benzylthio-CAMP qualitatively resembles the response of intact bag cell systems to either CAMP analogues or electrical stimulation, consistent with the hypothesis that CAMP induces a decrease in the membrane conductance to potassium ions.
Regional distribution of calcium- and cyclic adenosine 3':5'- monophosphate-regulated protein phosphorylation systems in mammalian brain. II. Soluble systems
Striking differences in the regional distribution of cytosolic protein phosphorylation systems in mammalian brain are demonstrated and may reflect highly specific functional roles for certain of these protein phosphORYlation systems.