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Independent movement of the voltage sensors in K_V2.1/K_V6.4 heterotetramers.

ABSTRACT: Heterotetramer voltage-gated K⁺ (K_V) channels K_V2.1/K_V6.4 display a gating charge-voltage (Q_V) distribution composed by two separate components. We use state dependent chemical accessibility to cysteines substituted in either K_V2.1 or K_V6.4 to assess the voltage sensor movements of each subunit. By comparing the voltage dependences of chemical modification and gating charge displacement, here we show that each gating charge component corresponds to a specific subunit forming the heterotetramer. The voltage sensors from K_V6.4 subunits move at more negative potentials than the voltage sensors belonging to K_V2.1 subunits. These results indicate that the voltage sensors from the tetrameric channels move independently. In addition, our data shows that 75% of the total charge is attributed to K_V2.1, while 25% to K_V6.4. Thus, the most parsimonious model for K_V2.1/K_V6.4 channels' stoichiometry is 3:1.

SUBMITTER: Bocksteins E

PROVIDER: S-EPMC5282584 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature

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Independent movement of the voltage sensors in KV2.1/KV6.4 heterotetramers.

Bocksteins Elke E Snyders Dirk J DJ Holmgren Miguel M

Scientific reports 20170131

Heterotetramer voltage-gated K+ (KV) channels KV2.1/KV6.4 display a gating charge-voltage (QV) distribution composed by two separate components. We use state dependent chemical accessibility to cysteines substituted in either KV2.1 or KV6.4 to assess the voltage sensor movements of each subunit. By comparing the voltage dependences of chemical modification and gating charge displacement, here we show that each gating ch ...[more]

PMID: 28139741

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