The TASK Family: Two-Pore Domain Background K+ Channels

  1. Douglas A. Bayliss1,2,
  2. Jay E. Sirois2 and
  3. Edmund M. Talley1
  1. 1Departments of Pharmacology and
  2. 2Anesthesiology, School of Medicine, University of Virginia, Charlottesville, VA
  1. Address correspondence to DAB. Email: dab3y{at}; fax 434-982-3878.


The recent identification of a distinct family of genes encoding two-pore domain potassium channels that generate background, or leak, K+ currents has permitted the analysis of the molecular underpinnings of these heretofore poorly understood currents. In the case of the TASK subfamily of channels, particularly TASK-1 (KCNK3) and TASK-3 (KCNK9), detailed characterization of cloned (and heterologously expressed) channels has revealed sets of unique properties that, together with information regarding sites of expression, have permitted identification of their native counterparts. This analysis has demonstrated that native TASK-like channels are subject to multiple forms of modulation (e.g., by protons, volatile anesthetics, oxygen tension, and receptor-mediated signaling pathways), which serve as a basis for participation in a number of physiological mechanisms. In this review, we describe the salient features of cloned TASK channels, present evidence for their functional expression in a number of tissues (e.g., brain, heart, and adrenal gland), and discuss possible roles for these channels in pH-dependent physiological processes (e.g., breathing and arousal) and in the clinical actions of inhalation anesthetics.


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