PKA and arachidonic acid activation of human recombinant ClC-2 chloride channels.
An HEK-293 cell line stably expressing the human recombinant ClC-2 Cl(-) channel was used in patch-clamp studies to study its regulation. The relative permeability P(x)/P(Cl) calculated from reversal potentials was I(-) > Cl(-) = NO(3)(-) = SCN(-)>/=Br(-). The absolute permeability calculated from conductance ratios was Cl(-) = Br(-) = NO(3)(-) >/= SCN(-) > I(-). The channel was activated by cAMP-dependent protein kinase (PKA), reduced extracellular pH, oleic acid (C:18 cisDelta9), elaidic acid (C:18 transDelta9), arachidonic acid (AA; C:20 cisDelta5,8,11,14), and by inhibitors of AA metabolism, 5,8,11,14-eicosatetraynoic acid (ETYA; C:20 transDelta5,8,11,14), alpha-methyl-4-(2-methylpropyl)benzeneacetic acid (ibuprofen), and 2-phenyl-1,2-benzisoselenazol-3-[2H]-one (PZ51, ebselen). ClC-2 Cl(-) channels were activated by a combination of forskolin plus IBMX and were inhibited by the cell-permeant myristoylated PKA inhibitor (mPKI). Channel activation by reduction of bath pH was increased by PKA and prevented by mPKI. AA activation of the ClC-2 Cl(-) channel was not inhibited by mPKI or staurosporine and was therefore independent of PKA or protein kinase C activation.
Tewari
K P
KP
Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0576, USA.
Malinowska
D H
DH
Sherry
A M
AM
Cuppoletti
J
J
D015117:5,8,11,14-Eicosatetraynoic Acid / Q000494:pharmacology; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D016718:Arachidonic Acid / Q000494:pharmacology / Q000502:physiology*; D001393:Azoles / Q000494:pharmacology; D000090007:CLC-2 Chloride Channels; D002460:Cell Line; D018118:Chloride Channels / Q000378:metabolism* / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004553:Electric Conductivity; D004789:Enzyme Activation / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007052:Ibuprofen / Q000494:pharmacology; D007477:Ions; D054833:Isoindoles; D009599:Nitroprusside / Q000494:pharmacology; D016566:Organoselenium Compounds / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011994:Recombinant Proteins / Q000378:metabolism
D000894:Anti-Inflammatory Agents, Non-Steroidal; D001393:Azoles; D000090007:CLC-2 Chloride Channels; D018118:Chloride Channels; D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D005230:Fatty Acids, Nonesterified; D007477:Ions; D054833:Isoindoles; D016566:Organoselenium Compounds; D011994:Recombinant Proteins; D015117:5,8,11,14-Eicosatetraynoic Acid; D009599:Nitroprusside; D016718:Arachidonic Acid; C042986:ebselen; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D007052:Ibuprofen