Calyculin A blocks bovine chromaffin cell calcium channels independently of phosphatase inhibition.
The specific phosphatase inhibitor, Calyculin-A (CL-A), decreases high-K stimulated catecholamine secretion in bovine chromaffin cells. This effect can be split into two components: one needs long exposures to the drug to be elicited, and is sensitive to the protein kinase-inhibitor K252a; the other is observed after short incubations of CL-A, and is insensitive to K252a. Here we report that the latter component is due to an external block, by CL-A, of chromaffin cell calcium channels in a voltage-dependent, reversible and phosphorylation-independent manner.
Gutiérrez
L M
LM
Departamento de Neuroquímica, Universidad de Alicante, Spain.
Viniegra
S
S
Quintanar
J L
JL
Reig
J A
JA
Sala
F
F
D000313:Adrenal Medulla / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000502:physiology*; D002227:Carbazoles / Q000494:pharmacology; D002417:Cattle; D002478:Cells, Cultured; D026121:Indole Alkaloids; D008387:Marine Toxins; D008564:Membrane Potentials / Q000187:drug effects; D010080:Oxazoles / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D002227:Carbazoles; D026121:Indole Alkaloids; D008387:Marine Toxins; D010080:Oxazoles; C059041:calyculin A; C049985:staurosporine aglycone; D011493:Protein Kinase C; D010749:Phosphoprotein Phosphatases