| Title |
|
|
|
The electrically silent Kv6.4 subunit confers hyperpolarized gating charge movement in Kv2.1/Kv6.4 heterotetrameric channels
| |
| Author |
|
|
|
| |
| Abstract |
|
|
|
| The voltage-gated K+ (Kv) channel subunit Kv6.4 does not form functional homotetrameric channels but co-assembles with Kv2.1 to form functional Kv2.1/Kv6.4 heterotetrameric channels. Compared to Kv2.1 homotetramers, Kv6.4 exerts a similar to 40 mV hyperpolarizing shift in the voltage-dependence of Kv2.1/Kv6.4 channel inactivation, without a significant effect on activation gating. However, the underlying mechanism of this Kv6.4-induced modulation of Kv2.1 channel inactivation, and whether the Kv6.4 subunit participates in the voltage-dependent gating of heterotetrameric channels is not well understood. Here we report distinct gating charge movement of Kv2.1/Kv6.4 heterotetrameric channels, compared to Kv2.1 homotetramers, as revealed by gating current recordings from mammalian cells expressing these channels. The gating charge movement of Kv2.1/Kv6.4 heterotetrameric channels displayed an extra component around the physiological K+ equilibrium potential, characterized by a second sigmoidal relationship of the voltage-dependence of gating charge movement. This distinct gating charge displacement reflects movement of the Kv6.4 voltage-sensing domain and has a voltage-dependency that matches the hyperpolarizing shift in Kv2.1/Kv6.4 channel inactivation. These results provide a mechanistic basis for the modulation of Kv2.1 channel inactivation gating kinetics by silent Kv6.4 subunits. |
| |
| Language |
|
|
|
English
| |
| Source (journal) |
|
|
|
PLoS ONE | |
| Publication |
|
|
|
2012
| |
| ISSN |
|
|
|
1932-6203
| |
| Volume/pages |
|
|
|
7:5(2012), 7 p.
| |
| Article Reference |
|
|
|
e37143
| |
| ISI |
|
|
|
000305341200044
| |
| Medium |
|
|
|
E-only publicatie
| |
| Full text (Publisher's DOI) |
|
|
| | |
| Full text (open access) |
|
|
| | |
|