KCNB2

Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shab-related subfamily. This member is a delayed rectifier potassium channel. The gene is expressed in gastrointestinal smooth muscle cells. [provided by RefSeq, Jul 2008]

Full Name

Potassium Voltage-Gated Channel Subfamily B Member 2

Function

Voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells. 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. 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. 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. 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.

Biological Process

Potassium ion transmembrane transportISS:UniProtKB
Potassium ion transportISS:UniProtKB
Protein homooligomerizationIEA:InterPro
Protein localization to plasma membraneISS:UniProtKB
Regulation of ion transmembrane transportIEA:UniProtKB-KW
Regulation of smooth muscle contractionManual Assertion Based On ExperimentTAS:ProtInc

Cellular Location

Cell membrane; Perikaryon; Cell projection, dendrite. Localized uniformly throughout cell bodies and dendrites. Colocalizes with KCNB1 to high-density somatodendritic clusters on cortical pyramidal neurons.

Topology

Cytoplasmic: 1-190
Helical: 191-212
Extracellular: 213-232
Helical: 233-254
Cytoplasmic: 255-265
Helical: 266-284
Extracellular: 285-296
Helical: 297-317
Cytoplasmic: 318-332
Helical: 333-354
Extracellular: 355-368
Helical: 369-388
Extracellular: 389-395
Helical: 396-424
Cytoplasmic: 425-911

PTM

Phosphorylated.