Recombinant Human Voltage-gated potassium channel subunit beta-2 (KCNAB2)

Function

Regulatory subunit of the voltage-gated potassium (Kv) Shaker channels composed of pore-forming and potassium-conducting alpha subunits and of regulatory beta subunits (PubMed:11825900, PubMed:7649300). The beta-2/KCNAB2 cytoplasmic subunit promotes potassium channel closure via a mechanism that does not involve physical obstruction of the channel pore (PubMed:11825900, PubMed:7649300). Promotes the inactivation of Kv1.4/KCNA4 and Kv1.5/KCNA5 alpha subunit-containing channels (PubMed:11825900, PubMed:7649300). Displays nicotinamide adenine dinucleotide phosphate (NADPH)-dependent aldoketoreductase activity by catalyzing the NADPH-dependent reduction of a wide range of aldehyde and ketone substrates (By similarity). Substrate specificity includes methylglyoxal, 9,10-phenanthrenequinone, prostaglandin J2, 4-nitrobenzaldehyde, 4-nitroacetophenone and 4-oxo-trans-2-nonenal (in vitro, no physiological substrate identified yet) (By similarity). The binding of oxidized and reduced nucleotide alters Kv channel gating and may contribute to dynamic fine tuning of cell excitability (By similarity). Contributes to the regulation of nerve signaling, and prevents neuronal hyperexcitability (By similarity)

Subcellular Location

Cytoplasm; Membrane (Peripheral membrane protein); Cell membrane (Peripheral membrane protein); Cell projection, axon; Synapse, synaptosome; Cytoplasm, cytoskeleton

Tissue Specificity

Detected in myelinated nerve fibers in the spinal cord, in the juxtaparanodal region of the nodes of Ranvier, but also in the paranodal region (PubMed:11086297). Detected in hippocampus (at protein level) (PubMed:21357749). Detected in hippocampus (PubMed:7649300)

Subunit

Homotetramer (By similarity). Interaction with tetrameric potassium channel alpha subunits gives rise to a heterooctamer (By similarity). Identified in potassium channel complexes containing KCNA1, KCNA2, KCNA4, KCNA5, KCNA6, KCNAB1, KCNAB2 and KCND3 (PubMed:11086297). Interacts (in unphosphorylated form) with MAPRE1 (By similarity). Forms a ternary complex with SQSTM1 and PRKCZ (By similarity)

• Mccormack K. et al. Alternative splicing of the human Shaker K+ channel beta 1 gene and functional expression of the beta 2 gene product. — FEBS Lett. (1995)
• McCormack K. et al. PubMed: CI-3E1CQN6NB1C2B (JAN-)
• Rae J.L. et al. PubMed: CI-4HHC5SKCIFCN3 (OCT-)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• Gregory S.G. et al. The DNA sequence and biological annotation of human chromosome 1. — Nature (2006)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Rasband M.N. et al. Subunit composition and novel localization of K+ channels in spinal cord. — J. Comp. Neurol. (2001)
• McCormack K. et al. Genetic analysis of the mammalian K+ channel beta subunit Kvbeta 2 (Kcnab2). — J. Biol. Chem. (2002)