Single-channel recordings of chloride currents in cultured human skeletal muscle

1992 ◽  
Vol 421 (2-3) ◽  
pp. 108-116 ◽  
Author(s):  
Ch. Fahlke ◽  
E. Zachar ◽  
R. R�del
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Single Channel ◽  
Chloride Currents ◽  
Single Channel Recordings

scholarly journals A central core disease mutation in the Ca2+-binding site of skeletal muscle ryanodine receptor impairs single-channel regulation

2019 ◽  
Vol 317 (2) ◽  
pp. C358-C365 ◽  
Author(s):  
Venkat R. Chirasani ◽  
Le Xu ◽  
Hannah G. Addis ◽  
Daniel A. Pasek ◽  
Nikolay V. Dokholyan ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Amino Acid ◽  
Missense Mutation ◽  
Ryanodine Receptor ◽  
Single Channel ◽  
Central Core ◽  
Central Core Disease ◽  
Hek293 Cells ◽  
Amino Acid Residues ◽  
Single Channel Recordings

Cryoelectron microscopy and mutational analyses have shown that type 1 ryanodine receptor (RyR1) amino acid residues RyR1-E3893, -E3967, and -T5001 are critical for Ca2+-mediated activation of skeletal muscle Ca2+ release channel. De novo missense mutation RyR1-Q3970K in the secondary binding sphere of Ca2+ was reported in association with central core disease (CCD) in a 2-yr-old boy. Here, we characterized recombinant RyR1-Q3970K mutant by cellular Ca2+ release measurements, single-channel recordings, and computational methods. Caffeine-induced Ca2+ release studies indicated that RyR1-Q3970K formed caffeine-sensitive, Ca2+-conducting channel in HEK293 cells. However, in single-channel recordings, RyR1-Q3970K displayed low Ca2+-dependent channel activity and greatly reduced activation by caffeine or ATP. A RyR1-Q3970E mutant corresponds to missense mutation RyR2-Q3925E associated with arrhythmogenic syndrome in cardiac muscle. RyR1-Q3970E also formed caffeine-induced Ca2+ release in HEK293 cells and exhibited low activity in the presence of the activating ligand Ca2+ but, in contrast to RyR1-Q3970K, was activated by ATP and caffeine in single-channel recordings. Computational analyses suggested distinct structural rearrangements in the secondary binding sphere of Ca2+ of the two mutants, whereas the interaction of Ca2+ with directly interacting RyR1 amino acid residues Glu3893, Glu3967, and Thr5001 was only minimally affected. We conclude that RyR1-Q3970 has a critical role in Ca2+-dependent activation of RyR1 and that a missense RyR1-Q3970K mutant may give rise to myopathy in skeletal muscle.

Two Types of ACh Receptors Contribute to Fast Channel Gating on Mouse Skeletal Muscle

1997 ◽  
Vol 78 (6) ◽  
pp. 2966-2974 ◽  
Author(s):  
Dawn Shepherd ◽  
Paul Brehm
Keyword(s):  
Skeletal Muscle ◽  
Single Channel ◽  
Channel Gating ◽  
Receptor Type ◽  
Open Probability ◽  
Mouse Skeletal Muscle ◽  
Single Channel Recordings ◽  
Open Time ◽  
Channel Open Time ◽  
Ach Receptors

Shepherd, Dawn and Paul Brehm. Two types of ACh receptors contribute to fast channel gating on mouse skeletal muscle. J. Neurophysiol. 78: 2966–2974, 1997. Single-channel recordings from mouse C2 myotubes indicate that maturation of skeletal muscle is accompanied by the appearance of two types of fast acetylcholine (ACh) receptor channels that are each functionally distinct from the embryonic receptor type present at early stages of differentiation. The embryonic receptor type has a low conductance (45 pS) and long channel open time, rendering slowly decaying synaptic currents. One fast channel type that appears during muscle maturation is distinguished from the embryonic receptor type on the basis of both higher conductance (65 pS) and shorter open time. However, single-channel recordings from differentiated mouse skeletal muscle cell line (C2) point to the existence of a second fast receptor type, which has a conductance similar to the embryonic receptor type (45 pS), yet significantly reduced mean channel open time. Analyses of individual channel function at high ACh concentrations directly demonstrate the coexistence of two kinetically distinct types of 45 pS ACh receptors. Openings by fast type and slow embryonic type of 45 pS receptors occurred in bursts, allowing distinction on the basis of both mean open time and open probability for individual receptors. The embryonic type of 45 pS receptor has an open time approximately twofold longer than the fast-receptor counterpart. Additional differences were reflected in the open probability distributions for fast and slow 45 pS receptor types. Both types of 45 pS receptor were kinetically distinguishable from the 65 pS receptor. We found no support for the idea that the slow and fast 45 pS receptor types result from the interconversion of dual gating modes involving the same receptor protein. Our results are consistent with the idea that the acquisition of fast synaptic current decay, required at mature neuromuscular synapses, is the result of the up-regulation of two distinct fast types of nicotinic ACh receptors during skeletal muscle development.

TGFß regulates metabolism of human skeletal muscle cells by miRNAs

2018 ◽  
Author(s):  
S Höckele ◽  
P Huypens ◽  
C Hoffmann ◽  
T Jeske ◽  
M Hastreiter ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Muscle Cells ◽  
Skeletal Muscle Cells ◽  
Human Skeletal Muscle Cells

IRAK-1/IRS-1 Signaling Cross Talk in Human Skeletal Muscle—Role in Insulin Resistance

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 159-OR
Author(s):  
THEODORE P. CIARALDI ◽  
SUNDER MUDALIAR ◽  
LIWU LI ◽  
ROSARIO SCALIA ◽  
XIAO JIAN SUN ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Cross Talk ◽  
Human Skeletal Muscle

1891-P: Palmitate-Enriched Lipid Ingestion Acutely Induces Insulin Resistance Associated with PKCγ Activation and Impaired Mitochondrial Function in Human Skeletal Muscle

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1891-P
Author(s):  
THERESIA SARABHAI ◽  
CHRYSI KOLIAKI ◽  
SABINE KAHL ◽  
DOMINIK PESTA ◽  
LUCIA MASTROTOTARO ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Mitochondrial Function ◽  
Human Skeletal Muscle

Human skeletal muscle insulin receptor substrate-1. Characterization of the cDNA, gene, and chromosomal localization

Diabetes ◽  
1993 ◽  
Vol 42 (7) ◽  
pp. 1041-1054 ◽  
Author(s):  
E. Araki ◽  
X. J. Sun ◽  
B. L. Haag ◽  
L. M. Chuang ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Insulin Receptor ◽  
Human Skeletal Muscle ◽  
Chromosomal Localization ◽  
Insulin Receptor Substrate ◽  
Insulin Receptor Substrate 1
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