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In vivo expression of G‐protein β 1 γ 2 dimer in adult mouse skeletal muscle alters L‐type calcium current and excitation–contraction coupling
Author(s) -
Weiss Norbert,
Legrand Claude,
Pouvreau Sandrine,
Bichraoui Hicham,
Allard Bruno,
Zamponi Gerald W.,
De Waard Michel,
Jacquemond Vincent
Publication year - 2010
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2010.191593
Subject(s) - skeletal muscle , chemistry , biophysics , voltage clamp , membrane potential , myocyte , patch clamp , receptor , microbiology and biotechnology , biology , endocrinology , biochemistry
A number of G‐protein‐coupled receptors are expressed in skeletal muscle but their roles in muscle physiology and downstream effector systems remain poorly investigated. Here we explored the functional importance of the G‐protein βγ (Gβγ) signalling pathway on voltage‐controlled Ca 2+ homeostasis in single isolated adult skeletal muscle fibres. A GFP‐tagged Gβ 1 γ 2 dimer was expressed in vivo in mice muscle fibres. The GFP fluorescence pattern was consistent with a Gβ 1 γ 2 dimer localization in the transverse‐tubule membrane. Membrane current and indo‐1 fluorescence measurements performed under voltage‐clamp conditions reveal a drastic reduction of both L‐type Ca 2+ current density and of peak amplitude of the voltage‐activated Ca 2+ transient in Gβ 1 γ 2 ‐expressing fibres. These effects were not observed upon expression of Gβ 2 γ 2 , Gβ 3 γ 2 or Gβ 4 γ 2 . Our data suggest that the G‐protein β 1 γ 2 dimer may play an important regulatory role in skeletal muscle excitation–contraction coupling.