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.[8][9][7]
Physiological role
Kv3.1/Kv3.2 conductance is necessary and kinetically optimized for high-frequency action potential generation.[9][10] 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.[7][8]
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).[7][9] This can be useful in identifying native channels.[9]
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.[11]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Haas 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.
S2CID24121259.
^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.
S2CID219195192.
^
abcdGutman 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.
S2CID219195192.