Calmodulin- and protein phosphorylation-independent release of catecholamines from PC-12 cells

Academic Article


  • Catecholamine secretion from PC-12 cells can be triggered by agents that increase intracellular Ca2+ and is enhanced by phorbol esters and agents that elevate intracellular cAMP concentrations. In mutant PC-12 cells lacking cAMP-dependent protein kinase (PK-A) in which protein kinase C (PK-C) was down-regulated, Ca2+-dependent secretion occurred normally but was no longer enhanced by cAMP or phorbol esters. In digitonin-permeabilized PC-12 cells that lacked PK-C and PK-A, a range of calmodulin (CaM) inhibitors failed to block Ca2+-triggered catecholamine release. Moreover, Mn2+, a CaM activator, failed to trigger catecholamine release whereas Ba2+, which does not activate CaM, supported secretion. These results indicate that the basic mechanism of stimulus/secretion coupling in PC-12 cells does not absolutely require a regulated protein phosphorylation- or calmodulin-dependent step. © 1988.
  • Published In

  • FEBS Letters  Journal
  • Digital Object Identifier (doi)

    Author List

  • Matthies HJG; Palfrey HC; Miller RJ
  • Start Page

  • 238
  • End Page

  • 242
  • Volume

  • 229
  • Issue

  • 2