Structural highlights
Function
[KCAB2_RAT] Accessory potassium channel protein which modulates the activity of the pore-forming alpha subunit. [KCNA2_RAT] Mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient.[1]
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 PubMed
Voltage sensors regulate the conformations of voltage-dependent ion channels and enzymes. Their nearly switchlike response as a function of membrane voltage comes from the movement of positively charged amino acids, arginine or lysine, across the membrane field. We used mutations with natural and unnatural amino acids, electrophysiological recordings, and x-ray crystallography to identify a charge transfer center in voltage sensors that facilitates this movement. This center consists of a rigid cyclic "cap" and two negatively charged amino acids to interact with a positive charge. Specific mutations induce a preference for lysine relative to arginine. By placing lysine at specific locations, the voltage sensor can be stabilized in different conformations, which enables a dissection of voltage sensor movements and their relation to ion channel opening.
A gating charge transfer center in voltage sensors.,Tao X, Lee A, Limapichat W, Dougherty DA, MacKinnon R Science. 2010 Apr 2;328(5974):67-73. PMID:20360102[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lev S, Moreno H, Martinez R, Canoll P, Peles E, Musacchio JM, Plowman GD, Rudy B, Schlessinger J. Protein tyrosine kinase PYK2 involved in Ca(2+)-induced regulation of ion channel and MAP kinase functions. Nature. 1995 Aug 31;376(6543):737-45. PMID:7544443 doi:http://dx.doi.org/10.1038/376737a0
- ↑ Tao X, Lee A, Limapichat W, Dougherty DA, MacKinnon R. A gating charge transfer center in voltage sensors. Science. 2010 Apr 2;328(5974):67-73. PMID:20360102 doi:328/5974/67
