Transmembrane domain length of viral K+ channels is a signal for mitochondria targeting

Jörg Balss, Panagiotis Papatheodorou, Mario Mehmel, Dirk Baumeister, Brigitte Hertel, Nicolas Delaroque, Franck C. Chatelain, Daniel L. Minor, James L. Van Etten, Joachim Rassow, Anna Moroni, Gerhard Thiel

Research output: Contribution to journalArticle

32 Scopus citations

Abstract

K+ channels operate in the plasma membrane and in membranes of organelles including mitochondria. The mechanisms and topogenic information for their differential synthesis and targeting is unknown. This article describes 2 similar viral K+ channels that are differentially sorted; one protein (Kesv) is imported by the Tom complex into the mitochondria, the other (Kcv) to the plasma membrane. By creating chimeras we discovered that mitochondrial sorting of Kesv depends on a hierarchical combination of N- and C-terminal signals. Crucial is the length of the second transmembrane domain; extending its C terminus by ≥2 hydrophobic amino acids redirects Kesv from the mitochondrial to the plasma membrane. Activity of Kesv in the plasma membrane is detected electrically or by yeast rescue assays only after this shift in sorting. Hence only minor structural alterations in a transmembrane domain are sufficient to switch sorting of a K+ channel between the plasma membrane and mitochondria.

Original languageEnglish (US)
Pages (from-to)12313-12318
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume105
Issue number34
DOIs
Publication statusPublished - Aug 26 2008

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Keywords

  • Algal viruses
  • Dual targeting
  • Esv-1
  • K+ channel sorting
  • PBCV-1

ASJC Scopus subject areas

  • General

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