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Structural highlights

Function

KCNB2_RAT Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells (PubMed:1550672). Channels open or close in response to the voltage difference across the membrane, letting potassium ions pass in accordance with their electrochemical gradient. Homotetrameric channels mediate a delayed-rectifier voltage-dependent outward potassium current that display rapid activation and slow inactivation in response to membrane depolarization (PubMed:1550672). Can form functional homotetrameric and heterotetrameric channels that contain variable proportions of KCNB1; channel properties depend on the type of alpha subunits that are part of the channel (PubMed:20202934). Can also form functional heterotetrameric channels with other alpha subunits that are non-conducting when expressed alone, such as KCNS1 and KCNS2, creating a functionally diverse range of channel complexes (PubMed:9305895). In vivo, membranes probably contain a mixture of heteromeric potassium channel complexes, making it difficult to assign currents observed in intact tissues to any particular potassium channel family member. Contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells (PubMed:1550672, PubMed:20202934).[UniProtKB:A6H8H5]^{[1] [2] [3]} 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.^[4]

See Also

• Potassium channel 3D structures

References

1. ↑ Hwang PM, Glatt CE, Bredt DS, Yellen G, Snyder SH. A novel K+ channel with unique localizations in mammalian brain: molecular cloning and characterization. Neuron. 1992 Mar;8(3):473-81. PMID:1550672 doi:10.1016/0896-6273(92)90275-i
2. ↑ Kihira Y, Hermanstyne TO, Misonou H. Formation of heteromeric Kv2 channels in mammalian brain neurons. J Biol Chem. 2010 May 14;285(20):15048-15055. PMID:20202934 doi:10.1074/jbc.M109.074260
3. ↑ Salinas M, Duprat F, Heurteaux C, Hugnot JP, Lazdunski M. New modulatory alpha subunits for mammalian Shab K+ channels. J Biol Chem. 1997 Sep 26;272(39):24371-9. PMID:9305895 doi:10.1074/jbc.272.39.24371
4. ↑ 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