Mode-switching of a voltage-gated cation channel is mediated by a protein kinase A-regulated tyrosine phosphatase.
Tyrosine kinases and tyrosine phosphatases are abundant in central nervous system tissue, yet the role of these enzymes in the modulation of neuronal excitability is unknown. Patch-clamp studies of an Aplysia voltage-gated cation channel now demonstrate that a tyrosine phosphatase endogenous to excised patches determines both the gating mode of the channel and the response of the channel to protein kinase A. Moreover, a switch in gating modes similar to that triggered by the phosphatase occurs at the onset of a prolonged change in the excitability of Aplysia bag cell neurons.
Wilson
G F
GF
Department of Pharmacology, Yale University, New Haven, Connecticut 06510.
Kaczmarek
L K
LK
D000818:Animals; D001048:Aplysia; D002412:Cations / Q000378:metabolism*; D020916:Conotoxins; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D015640:Ion Channel Gating; D008978:Mollusk Venoms / Q000494:pharmacology; D009474:Neurons / Q000378:metabolism*; D009596:Nitrophenols / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D010766:Phosphorylation; D017027:Protein Tyrosine Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology
D002412:Cations; D020916:Conotoxins; C059360:Conus textile toxin; D008978:Mollusk Venoms; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C008644:nitrophenylphosphate; D014638:Vanadates; D014443:Tyrosine; D017868:Cyclic AMP-Dependent Protein Kinases; D017027:Protein Tyrosine Phosphatases