title: Reciprocal modulation of ATP-sensitive K+ channel activity in rat ventricular myocytes by phosphorylation of tyrosine and serine/threonine residues.
abstract: The modulation of ATP-sensitive K+ channel (KATP) activity by specific phosphorylation or dephosphorylation of tyrosine and serine/threonine residues was examined in rat ventricular myocytes using the inside-out patch configuration of the patch clamp technique. The run-down process was suppressed by okadaic acid but accelerated by sodium orthovanadate. After run-down of the channels, the ATP-induced reactivation was blocked by H-7, but enhanced by genistein. The channel activity was decreased by protein phosphatase 2A. However, the activity of partially run-down channels was increased by protein tyrosine phosphatase 1B. Our results suggest that KATP channel activity can be inhibited by phosphorylation of tyrosine residues and stimulated by phosphorylation of serine/threonine residues.
authors.affiliation: Department of Pharmacology, Chonbuk National University Medical School, Chonju, South Korea.
authors.forename: Y G
authors.initials: YG
authors.lastname: Kwak
authors.forename: S K
authors.initials: SK
authors.lastname: Park
authors.forename: K P
authors.initials: KP
authors.lastname: Cho
authors.forename: S W
authors.initials: SW
authors.lastname: Chae
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D009206:Myocardium / Q000378:metabolism; D010766:Phosphorylation; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism; D013997:Time Factors; D014443:Tyrosine / Q000378:metabolism
chemical_list: D015221:Potassium Channels; D013912:Threonine; D014443:Tyrosine; D012694:Serine; D000255:Adenosine Triphosphate