Troponin I converts the skeletal muscle ryanodine receptor into a rectifying calcium release channel

Magdolna Varsányi, Sándor Sárközi, Csaba Szegedi, Anke Herzog, István Jóna

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The goal of our present studies has been to find novel ryanodine receptor (RyR1) interacting polypeptides that modulate the channel activity from the luminal side of RyR1. Using K+ as charge carrier for recording of single channel events here we demonstrate a very unexpected observation that troponin I substantially alters RyR's gating behavior, and that RyR1 in association with troponin I becomes a rectifying Ca2+ release channel. Troponin I rapidly locks the RyR1 in a non-conducting state only at a negative holding potential, and only when applied to the luminal side; switching to a positive holding potential results in the channel returning to its original activity, immediately. A hypothesis is proposed to account for how an intraluminally located, positively charged molecule might function as a RyR1 regulator under physiological conditions.

Original languageEnglish
Pages (from-to)155-158
Number of pages4
JournalFEBS letters
Volume515
Issue number1-3
DOIs
Publication statusPublished - Mar 27 2002

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Keywords

  • Calcium release
  • Rectifying channel
  • Ryanodine receptor
  • Skeletal muscle
  • Troponin I
  • Yeast two-hybrid screen

ASJC Scopus subject areas

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

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