The Properties of a Fluorescent Kv1.2 Channel Assembled from Concatemers of Alpha-Subunits

The α-subunits of the Kv1.2 potassium voltage-gated channel, whose function is to regulate neuronal conductivity in the central nervous system, form heterotetramers with α-subunits of related Kv1 channels, which differ in composition and stoichiometry. To study heterotetrameric channels in vitro, concatemers have been constructed by sequentially connecting the Kv1 α-subunits. The method for constructing concatemers that allow reproducing the properties of native channels requires detailed study. In this work, concatemers (dimers) of Kv1.2 α-subunits (mKate2-Kv1.2-Kv1.2) labeled with the fluorescent protein mKate2 were constructed and their expression was carried out in mouse neuroblastoma Neuro-2a cells. It was shown that the Kv1.2 channel assembled from concatemers is almost identical in its properties, namely, intracellular distribution, ability to integrate into the plasma membrane, efficiency of interaction with a peptide blocker, as well as in its electrophysiological characteristics, to the Kv1.2 channel based on monomeric mKate2-Kv1.2 α-subunits.