Heteromeric assembly of Kv2.1 with Kv9.3: Effect on the state dependence of inactivation

Daniel Kerschensteiner, Martin Stocker

Research output: Contribution to journalArticle

58 Scopus citations

Abstract

Modulatory α-subunits of Kv channels remain electrically silent after homomeric expression. Their interactions with Kv2 α-subunits via the amino- terminal domain promote the assembly of heteromeric functional channels. The kinetic features of these heteromers differ from those of Kv2 homomers, suggesting a distinct role in electrical signaling. This study investigates biophysical properties of channels emerging from the coexpression of Kv2.1 with the modulatory α-subunit Kv9.3. Changes relative to homomeric Kv2.1 concern activation, deactivation, inactivation, and recovery from inactivation. A detailed description of Kv2.1/Kv9.3 inactivation is presented. Kv2.1/Kv9.3 heteromers inactivate in a fast and complete fashion from intermediate closed states, but in a slow and incomplete manner from open states. Intermediate closed states of channel gating can be approached through partial activation or deactivation, according to a proposed qualitative model. These transitions are rate-limiting for Kv2.1/Kv9.3 inactivation. Finally, based on the kinetic description, we propose a putative function for Kv2.1/KV9.3 heteromers in rat heart.

Original languageEnglish
Pages (from-to)248-257
Number of pages10
JournalBiophysical Journal
Volume77
Issue number1
DOIs
StatePublished - Jul 1999
Externally publishedYes

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