Kv3.1 and Kv3.2 channels are prominently expressed in neurons that fire at high frequency. Kv3.2 channels are prominently expressed in brain (fast-spiking GABAergic interneurons of the neocortex, hippocampus, and caudate nucleus; terminal fields of thalamocortical projections), and in retinal ganglion cells.[4][5][3]
Physiological role
Kv3.1/Kv3.2 conductance is necessary and kinetically optimized for high-frequency action potential generation.[5][6] Sometimes in heteromeric complexes with Kv3.1; important for the high-frequency firing of fast spiking GABAergic interneurons and retinal ganglion cells; and GABA release via regulation of action potential duration in presynaptic terminals.[3][4]
Pharmacological properties
Kv3.2 currents in heterologous systems are highly sensitive to external tetraethylammonium (TEA) or 4-aminopyridine (4-AP) (IC50 values are 0.1 mM for both of the drugs).[3][5] This can be useful in identifying native channels.[5]
Transcript variants
There are four transcript variants of Kv3.2 gene: Kv3.2a, Kv3.2b, Kv3.2c, Kv3.2d. Kv3.2 isoforms differ only in their C-terminal sequence.[7]
References
↑ 1.01.1Haas M, Ward DC, Lee J, Roses AD, Clarke V, D'Eustachio P, Lau D, Vega-Saenz de Miera E, Rudy B (Mar 1994). "Localization of Shaw-related K+ channel genes on mouse and human chromosomes". Mamm Genome. 4 (12): 711–5. doi:10.1007/BF00357794. PMID8111118.
↑Gutman GA, Chandy KG, Grissmer S, Lazdunski M, McKinnon D, Pardo LA, Robertson GA, Rudy B, Sanguinetti MC, Stuhmer W, Wang X (Dec 2005). "International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels". Pharmacol Rev. 57 (4): 473–508. doi:10.1124/pr.57.4.10. PMID16382104.
↑ 3.03.13.23.3Gutman GA, Chandy KG, Grissmer S, Lazdunski M, McKinnon D, Pardo LA, Robertson GA, Rudy B, Sanguinetti MC, Stühmer W, Wang X (December 2005). "International Union of Pharmacology. LIII. Nomenclature and molecular relationships of voltage-gated potassium channels". Pharmacol. Rev. 57 (4): 473–508. doi:10.1124/pr.57.4.10. PMID16382104.
↑Rudy B, Chow A, Lau D, Amarillo Y, Ozaita A, Saganich M, Moreno H, Nadal MS, Hernandez-Pineda R, Hernandez-Cruz A, Erisir A, Leonard C, Vega-Saenz de Miera E (April 1999). "Contributions of Kv3 channels to neuronal excitability". Annals of the New York Academy of Sciences. 868 (1 MOLECULAR AND): 304–43. doi:10.1111/j.1749-6632.1999.tb11295.x. PMID10414303.
