- Peptide (C)ETQMENYDKHVTYNAERS, corresponding to amino acid residues 542-559 of rat KCNN2 (Accession P70604). Intracellular, C-terminal part.
- Western blot analysis of rat brain membranes:1. Anti-KCNN2 (KCa2.2, SK2) Antibody #APC-028), (1:200).
2. Anti-KCNN2 (KCa2.2, SK2) Antibody, preincubated with KCNN2/KCa2.2 Blocking Peptide (#BLP-PC028).
- Rat hippocampal slices (2 µg/ml) (Kramar, E.A. et al. (2004) J. Neurosci. 24, 5151.).
- Expression of KCNN2 (SK2) in rat cerebral cortexImmunohistochemical staining of KCNN2 channels using Anti-KCNN2 (KCa2.2, SK2) Antibody (#APC-028) in rat cerebral cortex. Picture showing the the third layer. Note that both neural (black arrows) and glial cells (green arrows) show intense staining. Reaction product is red and counterstain is H&E.
- Rat neurons from hippocampus (1:200) (Wang, W. et al. (2011) Neuropharmacology 60, 901.).
KCa2.2 (KCNN2, SK2) is a member of the Ca2+-activated K+ channel family with small conductance that includes KCa2.1 (KCNN1, SK1) and KCa2.3 (KCNN3, SK3). The channel is voltage insensitive and is activated by intracellular Ca2+ in the submicromolar range. It has, though, a similar topology to that of voltage-dependent K+ channels (KV channels), that is six transmembrane domains and intracellular N- and C-termini. The functional channel of all the KCa2 family members is a multimeric protein composed of four pore-forming subunits.
KCa2 channels are extremely sensitive to the levels of intracellular Ca2+ and concentrations as low as 300-700 nM can open the channels very rapidly (5-15 ms). Hence, the KCa2 channels are highly sensitive and fast Ca2+ sensors resembling other known Ca2+-binding proteins. This type of Ca2+-dependent activation is achieved by the constitutive binding of the KCa2 channels to calmodulin, a highly expressed Ca2+-binding protein via a calmodulin-binding domain situated at the cytoplasmic C-terminus.
Pharmacologically, the KCa2 channels are the only known targets of the bee venom toxin Apamin, with KCa2.1 being the least sensitive, KCa2.2 the most sensitive and KCa2.3 showing intermediate sensitivity.
KCa2.2 is predominantly expressed in the nervous system although expression in endothelial cells, heart and liver has been described.
KCa2.2 is known to be involved in the regulation of neuronal excitability. They do so mainly via a phenomenon known as after hyperpolarization in which KCa2 channels open in response to increased intracellular Ca2+ concentrations that result from the entry of extracellular Ca2+ through voltage-dependent Ca2+ channels during action potentials. In this way, KCa2 channels effectively form a Ca2+-mediated feedback loop.
Species reactivity key:
Anti-KCNN2 (KCa2.2, SK2) Antibody (#APC-028) is a highly specific antibody directed against an epitope of the rat protein. The antibody can be used in western blot, immunocytochemistry, immunohistochemistry, and immunoprecipitation applications. It has been designed to recognize KCNN2 from human, rat, and mouse samples.
- Mouse brain lysate.
Deng, P.Y. et al. (2019) J. Neurosci. 39, 28.
- Rat brain lysate (1:1000).
Rau, A.R. et al. (2015) J. Neurosci. 35, 9730.
- Rat brain lysate (1:500).
Larson, R.A. et al. (2015) Am. J. Physiol. 308, H1547.
- Mouse isolated mouse atria and HL-1 cell lysate (1:200).
Yi, F. et al. (2015) J. Biol. Chem. 290, 7016.
- Canine LA and PV cardiomyocytes (1:200).
Qi, X.Y. et al. (2014) Circulation 129, 430.
- Rat hippocampus (1:1000).
Brewster, A.L. et al. (2013) PLoS ONE 8, e57808.
- Human and mouse heart.
Xu, Y. et al. (2003) J. Biol. Chem. 278, 49085.
- Human Jurkat T cells (1.5 µg/ml).
Desai, R. et al. (2000) J. Biol. Chem. 275, 39954.
- Rat hippocampal slices (2 µg/ml).
Kramar, E.A. et al. (2004) J. Neurosci. 24, 5151.
- Rat hippocampal neurons (1:200).
Wang, W. et al. (2011) Neuropharmacology 60, 901.
- Deardorff, A.S. et al. (2013) J. Physiol. 591, 875.
- Gui, L. et al. (2013) Am. J. Physiol. 304, H118.
- Sorensen, C.M. et al. (2011) Pflugers Arch. 462, 655.
- Belmeguenai, A. et al. (2010) J. Neurosci. 30, 13630.
- Hopf, F.W. et al. (2010) Neuron 65, 682.
- Murthy, V. et al. (2009) Mol. Cell. Neurosci. 40, 39.
- Waring, D.W. et al. (2009) Endocrinology 150, 2264.
- Morimoto, T. et al. (2007) J. Pharmacol. Sci. 104, 94.
- Nakajima, H. et al. (2007) J. Neurochem. 103, 2428.
- Özgen, N. et al. (2007) Cardiovasc. Res. 75, 758.
- Brosh, I. et al. (2006) J. Neurophysiol. 96, 1728.
- McNeish, A.J. et al. (2006) Stroke 37, 1277.
- Moriguchi, S. et al. (2006) Proc. Natl. Acad. Sci. U.S.A. 103, 10811.
- Ren, Y. et al. (2006) J. Biol. Chem. 281, 11769.
- Tiwari-Woodroof. S. et al. (2006) Am. J. Physiol. 291, 687.
- Yamazaki, D. et al. (2006) J. Biol. Chem. 281, 38430.
- Conforti, L. et al. (2003) J. Immunol. 170, 695.
- Tamarina, N.A. et al (2003) Diabetes 52, 2000.
- Guinea pig Anti-KCNN2 (KCa2.2, SK2) Antibody (#APC-028-GP) is raised in guinea pig and can be used in multiplex staining studies in conjunction with any of our antibodies raised in rabbit. This antibody has been raised against the same epitope as #APC-028.