Trypsin-sensitive, rapid inactivation of a calcium-activated potassium channel.
Most calcium-activated potassium channels couple changes in intracellular calcium to membrane excitability by conducting a current with a probability that depends directly on submembrane calcium concentration. In rat adrenal chromaffin cells, however, a large conductance, voltage- and calcium-activated potassium channel (BK) undergoes rapid inactivation, suggesting that this channel has a physiological role different than that of other BK channels. The inactivation of the BK channel, like that of the voltage-gated Shaker B potassium channel, is removed by trypsin digestion and channels are blocked by the Shaker B amino-terminal inactivating domain. Thus, this BK channel shares functional and possibly structural homologies with other inactivating voltage-gated potassium channels.
Solaro
C R
CR
Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110.
Lingle
C J
CJ
D000311:Adrenal Glands / Q000502:physiology; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D002838:Chromaffin System / Q000502:physiology; D004553:Electric Conductivity; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D014357:Trypsin / Q000494:pharmacology*
D015221:Potassium Channels; D014357:Trypsin; D002118:Calcium