SK4 encodes intermediate conductance Ca2+-activated K+ channels in mouse urinary bladder smooth muscle cells.
The single channel current of intermediate conductance Ca2 +-activated K+ channel (IK channel) was measured in mouse urinary bladder myocytes (MBM), and the molecular basis of the channel was suggested to be the SK4 subtype by RT-PCR. Among Ca2+-activated K+ channel subtypes (SK2, SK3, SK4 and BK), the mRNAs of SK4 and BK were predominantly expressed in MBM. IK channel currents recorded from MBM showed: 38.7 pS slope conductance under symmetrical 140 mM K+ conditions, Ca2+-dependent activation, and blockade by charybdotoxin and econazole. These results strongly suggest that SK4 encodes IK channels in MBM.
Ohya
S
S
Department of Molecular and Cellular Pharmacology, Faculty of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.
Kimura
S
S
Kitsukawa
M
M
Muraki
K
K
Watanabe
M
M
Imaizumi
Y
Y
D000818:Animals; D002118:Calcium / Q000378:metabolism; D004594:Electrophysiology; D066298:In Vitro Techniques; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; D051379:Mice; D009130:Muscle, Smooth / Q000378:metabolism* / Q000502:physiology; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution; D001743:Urinary Bladder / Q000378:metabolism* / Q000502:physiology
D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; C496925:Kcnn4 protein, mouse; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D012333:RNA, Messenger; D002118:Calcium