KCNAB1 PrEST Antigen

Protein function: Cytoplasmic potassium channel subunit that modulates the characteristics of the channel-forming alpha-subunits (PubMed:7499366, PubMed:7603988, PubMed:17156368,PubMed:17540341, PubMed:19713757). Modulates action potentials via its effect on the pore-forming alpha subunits. Promotes expression of the pore-forming alpha subunits at the cell membrane, and thereby increases channel activity. Mediates closure of delayed rectifier potassium channels by physically obstructing the pore via its N-terminal domain and increases the speed of channel closure for other family members (PubMed:9763623). Promotes the closure of KCNA1, KCNA2 and KCNA5 channels (PubMed:7499366, PubMed:7890032, PubMed:7603988, PubMed:7649300, PubMed:8938711, PubMed:12077175, PubMed:12130714, PubMed:15361858, PubMed:17540341, PubMed:19713757). Accelerates KCNA4 channel closure (PubMed:7890032, PubMed:7649300, PubMed:7890764, PubMed:9763623). Accelerates the closure of heteromeric channels formed by KCNA1 and KCNA4 (PubMed:17156368). Accelerates the closure of heteromeric channels formed by KCNA2, KCNA5 and KCNA6. Isoform KvB1.2 has no effect on KCNA1, KCNA2 or KCNB1 (PubMed:7890032, PubMed:7890764). Enhances KCNB1 and KCNB2 channel activity. Binds NADPH, this is required for efficient down- regulation of potassium channel activity (PubMed:17540341). Has NADPH- dependent aldoketoreductase activity. Oxidation of the bound NADPH strongly decreases N-type inactivation of potassium channel activity. [The UniProt Consortium] Buffer: PBS and 1M Urea, pH 7.4.