Down-regulation of protein kinase C and kinase inhibitors dissociate short- and long-term enhancement produced by one-trial conditioning of Hermissenda

1993 ◽  
Vol 69 (2) ◽  
pp. 636-641 ◽  
Author(s):  
T. Crow ◽  
J. Forrester
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase Inhibitors ◽  
Protein Kinase Inhibitors ◽  
Cellular Plasticity ◽  
Short Term ◽  
Down Regulation ◽  
Kinase C ◽  
Short And Long Term

1. The visual system of Hermissenda has been studied extensively as a site of cellular plasticity produced by classical conditioning. Previous research has shown that one-trial conditioning, consisting of light paired with serotonin (5-HT) results in short- and long-term enhancement of light-elicited generator potentials in identified type B-photoreceptors. Recent evidence suggests that 5-HT exerts its effects on the induction of short-term enhancement by activation of protein kinase C (PKC), a Ca(2+)-activated and phospholipid-dependent protein kinase. However, the contribution of protein kinases in general, and specifically PKC in long-term enhancement has not been established. 2. The protein kinase inhibitors H-7 and sphingosine blocked the induction of short-term enhancement when applied before one-trial conditioning. However, the conditions that are sufficient to block the induction of short-term enhancement do not block long-term enhancement. Sphingosine and H-7 do not block the induction and expression of long-term enhancement when applied before one-trial conditioning. 3. Pretreatment before conditioning with 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which leads to down-regulation of PKC, also did not block long-term enhancement. Down-regulation by itself did not produce enhancement, although the transient peak of light-elicited generator potentials was reduced by pretreatment with TPA. 4. The results suggest that the induction of short- and long-term enhancement involve parallel processes, and thus the expression of long-term cellular plasticity produced by one-trial conditioning does not depend on the induction or expression of short-term enhancement.

scholarly journals Protein kinase C regulation of p-glycoprotein-mediated xenobiotic secretion in renal proximal tubule

1998 ◽  
Vol 275 (5) ◽  
pp. F785-F795 ◽  
Author(s):  
David S. Miller ◽  
Caroline R. Sussman ◽  
J. Larry Renfro
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Proximal Tubule ◽  
Kinase Inhibitors ◽  
Primary Cultures ◽  
Renal Proximal Tubule ◽  
Protein Kinase Inhibitors ◽  
Drug Accumulation ◽  
Kinase C ◽  
P Glycoprotein

Fluorescence microscopy, fluorescent substrates [daunomycin and a fluorescent cyclosporin A (CSA) derivative] and digital image analysis were used to examine the role of protein kinase C (PKC) in the control of p-glycoprotein in killifish renal proximal tubules. PKC activators, phorbol ester (phorbol 12-myristate 13-acetate, PMA) and dioctylglycerol, reduced luminal drug accumulation, and protein kinase inhibitors, staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7), increased luminal accumulation; a PMA analog that does not activate PKC was without effect. PMA effects were blocked by staurosporine. The increase in luminal fluorescence caused by staurosporine was blocked by the p-glycoprotein substrate, CSA, indicating that this component of transport was indeed mediated by p-glycoprotein. Neither PMA, dioctylglycerol, nor protein kinase inhibitors altered cellular drug accumulation. Finally, in primary cultures of flounder proximal tubule cells, PMA decreased transepithelial [3H]daunomycin secretion. This pharmacological approach demonstrates that in teleost renal proximal tubule, p-glycoprotein-mediated xenobiotic secretion is negatively correlated with changes in PKC activity, a finding that conflicts with results from studies using mammalian tumor cells that express p-glycoprotein.

scholarly journals Protein Kinase C-Gamma Knockout Mice Show Impaired Hippocampal Short-Term Memory While Preserved Long-Term Memory

2020 ◽  
Author(s):  
Maria Gomis-González ◽  
Lorena Galera-López ◽  
Marc Ten-Blanco ◽  
Arnau Busquets-Garcia ◽  
Thomas Cox ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Knockout Mice ◽  
Short Term Memory ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Kinase C ◽  
Protein Kinase C Gamma

scholarly journals Role of Protein Kinase C (PKC) in Short- and Long-Term Cellular Responses

1988 ◽  
Vol 12 ◽  
pp. 73-79 ◽  
Author(s):  
Doriano Fabbro ◽  
Nachman Mazurek ◽  
Christoph Borner ◽  
Jean-François Conscience ◽  
Paul Erne
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Cellular Responses ◽  
Kinase C ◽  
Short And Long Term

scholarly journals p53 Is Necessary for the Apoptotic Response Mediated by a Transient Increase of Ras Activity

2002 ◽  
Vol 22 (9) ◽  
pp. 2928-2938 ◽  
Author(s):  
Peihong Ma ◽  
Maureen Magut ◽  
XinBin Chen ◽  
Chang-Yan Chen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Suppressor P53 ◽  
Wild Type ◽  
Apoptotic Response ◽  
Kinase C ◽  
The Status ◽  
Short And Long Term

ABSTRACT The tumor suppressor p53 eliminates cancer-prone cells via multiple mechanisms, including apoptosis. Ras elicits apoptosis in cells after protein kinase C (PKC) downregulation. However, the role of p53 in Ras-mediated apoptosis has not been fully investigated. Here, we demonstrate that mouse fibroblasts that express wild-type p53 are more susceptible to apoptosis elicited by PKC inhibition if Ras is transiently expressed or upregulated as opposed to stably expressed. In the latter case, p53 is frequently mutated. Transiently increased Ras activity induces Bax, and PKC inhibition augments this induction. Overexpression of E6 inactivates p53 and thereby suppresses both Bax induction and apoptosis. In contrast, Bax is not induced in stable ras transfectants, regardless of PKC inhibition. The data suggest that short- and long-term activation of Ras use a different mechanism(s) to initiate apoptosis. The status of p53 may contribute to such differences.

scholarly journals Protein kinase C regulation of organic anion transport in renal proximal tubule

1998 ◽  
Vol 274 (1) ◽  
pp. F156-F164 ◽  
Author(s):  
David S. Miller
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phorbol Ester ◽  
Kinase Inhibitors ◽  
Organic Anion ◽  
Anion Transport ◽  
Protein Kinase Inhibitors ◽  
Organic Anion Transport ◽  
Kinase C ◽  
Tissue Fluorescence

Fluorescence microscopy and digital image analysis were used to examine the role of protein kinase C (PKC) in the control of organic anion (fluorescein, FL) transport in killifish renal proximal tubules. Phorbol ester (1–100 nM) reduced cellular and luminal accumulation of FL, and protein kinase inhibitors [staurosporine and 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine, 10–1,000 nM] increased cellular and luminal accumulation. Phorbol ester effects were blocked by staurosporine. The increases in tissue fluorescence caused by staurosporine were blocked by p-aminohippurate, indicating that they represent increased FL transport on the organic anion system. Neither phorbol ester nor staurosporine had any effects on the cell-to-lumen transport of a fluorescent organic anion that was generated intracellularly from a nonfluorescent, uncharged precursor. Finally, studies with a fluorescent PKC inhibitor showed that phorbol ester caused PKC translocation from cytoplasm to the plasma membrane. Together, these findings indicate that renal organic anion transport is negatively correlated with PKC activity and that PKC directly or indirectly controls the basolateral step in transport.

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