Formation of intermediate-conductance calcium-activated potassium channels by interaction of Slack and Slo subunits

• DOI: 10.1038/2176
• Publication Date: 2002-07-26T08:47:57Z
• Authors: William J. Joiner; Michael D. Tang; Lu-Yang Wang; Steven I. Dworetzky; Christopher G. Bo...; Li Gan; Valentin K. Gribkoff; Leonard K. Kaczmarek
• Keywords: Calcium-activated potassium channel; SK channel; BK channel; N-type calcium channel

Large-conductance calcium-activated potassium channels (maxi-K channels) have an essential role in the control of excitability and secretion. Only one gene Slo is known to encode maxi-K channels, which are sensitive to both membrane potential and intracellular calcium. We have isolated a potassium channel gene called Slack that is abundantly expressed in the nervous system. Slack channels rectify outwardly with a unitary conductance of about 25-65 pS and are inhibited by intracellular calcium. However, when Slack is co-expressed with Slo, channels with pharmacological properties and single-channel conductances that do not match either Slack or Slo are formed. The Slack/Slo channels have intermediate conductances of about 60-180 pS and are activated by cytoplasmic calcium. Our findings indicate that some intermediate-conductance channels in the nervous system may result from an interaction between Slack and Slo channel subunits.