3eb3
Voltage-dependent K+ channel beta subunit (W121A) in complex with cortisoneVoltage-dependent K+ channel beta subunit (W121A) in complex with cortisone
Structural highlights
FunctionKCAB2_RAT Accessory potassium channel protein which modulates the activity of the pore-forming alpha subunit. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Shaker family voltage-dependent potassium channels (Kv1) are expressed in a wide variety of cells and are essential for cellular excitability. In humans, loss-of-function mutations of Kv1 channels lead to hyperexcitability and are directly linked to episodic ataxia and atrial fibrillation. All Kv1 channels assemble with beta subunits (Kv betas), and certain Kv betas, for example Kv beta 1, have an N-terminal segment that closes the channel by the N-type inactivation mechanism. In principle, dissociation of Kv beta 1, although never reported, should eliminate inactivation and thus potentiate Kv1 current. We found that cortisone increases rat Kv1 channel activity by binding to Kv beta 1. A crystal structure of the Kv beta-cortisone complex was solved to 1.82-A resolution and revealed novel cortisone binding sites. Further studies demonstrated that cortisone promotes dissociation of Kv beta. The new mode of channel modulation may be explored by native or synthetic ligands to fine-tune cellular excitability. Cortisone dissociates the Shaker family K+ channels from their beta subunits.,Pan Y, Weng J, Kabaleeswaran V, Li H, Cao Y, Bhosle RC, Zhou M Nat Chem Biol. 2008 Nov;4(11):708-14. Epub 2008 Sep 21. PMID:18806782[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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