Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2, also known as KCNN2, is a protein which in humans is encoded by the KCNN2 gene.[1] KCNN2 is an ion channel protein also known as KCa2.2.[2]
Action potentials in vertebrate neurons are followed by an afterhyperpolarization (AHP) that may persist for several seconds and may have profound consequences for the firing pattern of the neuron. Each component of the AHP is kinetically distinct and is mediated by different calcium-activated potassium channels. The KCa2.2 protein is activated before membrane hyperpolarization and is thought to regulate neuronal excitability by contributing to the slow component of synaptic AHP. KCa2.2 is an integral membrane protein that forms a voltage-independent calcium-activated channel with three other calmodulin-binding subunits. This protein is a member of the calcium-activated potassium channel family. Two transcript variants encoding different isoforms have been found for the KCNN2 gene.[2]
In a study SK2 (KCNN2) potassium channel was overexpressed in the basolateral amygdala using a herpes simplex viral system. This reduced anxiety and stress-induced corticosterone secretion at a systemic level. SK2 overexpression also reduced dendritic arborization of the amygdala neurons.[3]
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Schumacher MA, Rivard AF, Bächinger HP, Adelman JP (2001). "Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin". Nature. 410 (6832): 1120–4. doi:10.1038/35074145. PMID11323678.
Miller MJ, Rauer H, Tomita H, et al. (2001). "Nuclear localization and dominant-negative suppression by a mutant SKCa3 N-terminal channel fragment identified in a patient with schizophrenia". J. Biol. Chem. 276 (30): 27753–6. doi:10.1074/jbc.C100221200. PMID11395478.
Piotrowska AP, Solari V, Puri P (2003). "Distribution of Ca2+-activated K channels, SK2 and SK3, in the normal and Hirschsprung's disease bowel". J. Pediatr. Surg. 38 (6): 978–83. doi:10.1016/S0022-3468(03)00138-6. PMID12778407.
Xu Y, Tuteja D, Zhang Z, et al. (2004). "Molecular identification and functional roles of a Ca2+-activated K+ channel in human and mouse hearts". J. Biol. Chem. 278 (49): 49085–94. doi:10.1074/jbc.M307508200. PMID13679367.
Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID14702039.
Feranchak AP, Doctor RB, Troetsch M, et al. (2004). "Calcium-dependent regulation of secretion in biliary epithelial cells: the role of apamin-sensitive SK channels". Gastroenterology. 127 (3): 903–13. doi:10.1053/j.gastro.2004.06.047. PMID15362045.
Lu L, Zhang Q, Timofeyev V, et al. (2007). "Molecular coupling of a Ca2+-activated K+ channel to L-type Ca2+ channels via alpha-actinin2". Circ. Res. 100 (1): 112–20. doi:10.1161/01.RES.0000253095.44186.72. PMID17110593.
Morimoto T, Ohya S, Hayashi H, et al. (2007). "Cell-cycle-dependent regulation of Ca2+-activated K+ channel in Jurkat T-lymphocyte". J. Pharmacol. Sci. 104 (1): 94–8. doi:10.1254/jphs.SC0070032. PMID17452806.