Ca2+-activated K+ channels: from protein complexes to function.
Molecular research on ion channels has demonstrated that many of these integral membrane proteins associate with partner proteins, often versatile in their function, or even assemble into stable macromolecular complexes that ensure specificity and proper rate of the channel-mediated signal transduction. Calcium-activated potassium (K(Ca)) channels that link excitability and intracellular calcium concentration are responsible for a wide variety of cellular processes ranging from regulation of smooth muscle tone to modulation of neurotransmission and control of neuronal firing pattern. Most of these functions are brought about by interaction of the channels' pore-forming subunits with distinct partner proteins. In this review we summarize recent insights into protein complexes associated with K(Ca) channels as revealed by proteomic research and discuss the results available on structure and function of these complexes and on the underlying protein-protein interactions. Finally, the results are related to their significance for the function of K(Ca) channels under cellular conditions.
Institute of Physiology II, University of Freiburg, and Centre for Biological Signalling Studies (Bioss),Freiburg, Germany. bernd.fakler@physiologie.uni-freiburg.de
Henrike
H
Berkefeld
Bernd
B
Fakler
Uwe
U
Schulte
D000818:Animals; D005786:Gene Expression Regulation / Q000502:physiology; D051036:Large-Conductance Calcium-Activated Potassium Channels / Q000502:physiology; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000502:physiology*; D024681:Potassium Channels, Calcium-Activated / Q000502:physiology*; D011487:Protein Conformation; D021381:Protein Transport; D040901:Proteomics; D051640:Small-Conductance Calcium-Activated Potassium Channels / Q000502:physiology
D051036:Large-Conductance Calcium-Activated Potassium Channels; D046912:Multiprotein Complexes; D024681:Potassium Channels, Calcium-Activated; D051640:Small-Conductance Calcium-Activated Potassium Channels