The sarcoplasmic-endoplasmic reticulum Ca2+ ATPase 2b regulates the Ca2+ transients elicited by P2Y2 activation in PC Cl3 thyroid cells.
In PC Cl3 cells, a continuous, fully differentiated rat thyroid cell line, P2Y(2) purinoceptor activation provoked a transient increase of [Ca(2+)](i), followed by a decreasing sustained phase. The alpha and beta1 protein kinase C (PKC) inhibitor Gö6976 decreased the rate of decrement to the basal [Ca(2+)](i) level and increased the peak of Ca(2+) entry of the P2Y(2)-provoked Ca(2+)transients. These effects of Gö 6976 were not caused by an increased permeability of the plasma membrane, since the Mn(2+) and Ba(2+) uptake were not changed by Gö 6976. Similarly, the Na(+)/Ca(2+) exchanger was not implicated, since the rate of decrement to the basal [Ca(2+)](i) level was equally decreased in physiological and Na(+)-free buffers, in the presence of Gö 6976. On the contrary, the activity of the sarcoplasmic-endoplasmic reticulum Ca(2+)ATPase (SERCA) 2b was profoundly affected by Gö 6976 since the drug was able to completely inhibit the stimulation of the SERCA 2b activity elicited by P2-purinergic agonists. Finally, the PKC activator phorbol myristate acetate had effects opposite to Gö 6976, in that it markedly increased the rate of decrement to the basal [Ca(2+)](i) level after P2Y(2) stimulation and also increased the activity of SERCA 2b. These results suggest that SERCA 2b plays a role in regulating the sustained phase of Ca(2+) transients caused by P2Y(2) stimulation.
Ulianich
Luca
L
Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Università degli Studi di Lecce, Ecotekne, Via Provinciale per Monteroni, 73100 Lecce, Italy.
Elia
Maria Giovanna
MG
Treglia
Antonella Sonia
AS
Muscella
Antonella
A
Di Jeso
Bruno
B
Storelli
Carlo
C
Marsigliante
Santo
S
D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000378:metabolism; D001693:Biological Transport, Active; D002118:Calcium / Q000032:analysis / Q000378:metabolism*; D002227:Carbazoles / Q000494:pharmacology; D002460:Cell Line; D004789:Enzyme Activation; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D008345:Manganese / Q000378:metabolism; D008856:Microscopy, Fluorescence; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D058473:Receptors, Purinergic P2Y2; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019284:Thapsigargin / Q000032:analysis; D013961:Thyroid Gland / Q000201:enzymology*; D014544:Uridine Triphosphate / Q000378:metabolism / Q000494:pharmacology
C506948:Atp2a2 protein, rat; D002227:Carbazoles; D007211:Indoles; D008301:Maleimides; C546387:P2ry2 protein, rat; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; C081021:Go 6976; D001464:Barium; D008345:Manganese; D019284:Thapsigargin; D000255:Adenosine Triphosphate; D011493:Protein Kinase C; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D014544:Uridine Triphosphate