Nutrient restriction differentially modulates the mammalian target of rapamycin signaling and the ubiquitin-proteasome system in skeletal muscle of cows and their fetuses1

2005 ◽  
Vol 83 (1) ◽  
pp. 117-123 ◽  
Author(s):  
M. Du ◽  
M. J. Zhu ◽  
W. J. Means ◽  
B. W. Hess ◽  
S. P. Ford
Keyword(s):  
Skeletal Muscle ◽  
Mammalian Target Of Rapamycin ◽  
Ubiquitin Proteasome System ◽  
Target Of Rapamycin ◽  
Nutrient Restriction ◽  
Ubiquitin Proteasome

The ubiquitin–proteasome system and skeletal muscle wasting

2005 ◽  
Vol 41 ◽  
pp. 173-186 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Proteolytic Enzymes ◽  
Cathepsin L ◽  
Ubiquitin Proteasome System ◽  
Complete Breakdown ◽  
Skeletal Muscle Proteins ◽  
Ubiquitin Proteasome ◽  
Tripeptidyl Peptidase Ii ◽  
F Box Protein

The ubiquitin–proteasome system (UPS) is believed to degrade the major contractile skeletal muscle proteins and plays a major role in muscle wasting. Different and multiple events in the ubiquitination, deubiquitination and proteolytic machineries are responsible for the activation of the system and subsequent muscle wasting. However, other proteolytic enzymes act upstream (possibly m-calpain, cathepsin L, and/or caspase 3) and downstream (tripeptidyl-peptidase II and aminopeptidases) of the UPS, for the complete breakdown of the myofibrillar proteins into free amino acids. Recent studies have identified a few critical proteins that seem necessary for muscle wasting {i.e. the MAFbx (muscle atrophy F-box protein, also called atrogin-1) and MuRF-1 [muscle-specific RING (really interesting new gene) finger 1] ubiquitin–protein ligases}. The characterization of their signalling pathways is leading to new pharmacological approaches that can be useful to block or partially prevent muscle wasting in human patients.

The ubiquitin–proteasome system and skeletal muscle wasting

2005 ◽  
Vol 41 (1) ◽  
pp. 173 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Ubiquitin Proteasome System ◽  
Skeletal Muscle Wasting ◽  
Ubiquitin Proteasome

scholarly journals Identification of the MuRF1 skeletal muscle ubiquitylome through quantitative proteomics

Function ◽  
2021 ◽  
Author(s):  
Leslie M Baehr ◽  
David C Hughes ◽  
Sarah A Lynch ◽  
Delphi Van Haver ◽  
Teresa Mendes Maia ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Potential Role ◽  
Ubiquitin Proteasome System ◽  
In Vivo Electroporation ◽  
Adult Mice ◽  
Expression Of Genes ◽  
Regulation Of Metabolism ◽  
Ubiquitin Proteasome

Abstract MuRF1 (TRIM63) is a muscle-specific E3 ubiquitin ligase and component of the ubiquitin proteasome system. MuRF1 is transcriptionally upregulated under conditions that cause muscle loss, in both rodents and humans, and is a recognized marker of muscle atrophy. In this study, we used in vivo electroporation to determine if MuRF1 overexpression alone can cause muscle atrophy and, in combination with ubiquitin proteomics, identify the endogenous MuRF1 substrates in skeletal muscle. Overexpression of MuRF1 in adult mice increases ubiquitination of myofibrillar and sarcoplasmic proteins, increases expression of genes associated with neuromuscular junction instability, and causes muscle atrophy. A total of 169 ubiquitination sites on 56 proteins were found to be regulated by MuRF1. MuRF1-mediated ubiquitination targeted both thick and thin filament contractile proteins, as well as, glycolytic enzymes, deubiquitinases, p62, and VCP. These data reveal a potential role for MuRF1 in not only the breakdown of the sarcomere, but also the regulation of metabolism and other proteolytic pathways in skeletal muscle.

Mechanical signal transduction in skeletal muscle growth and adaptation

2005 ◽  
Vol 98 (5) ◽  
pp. 1900-1908 ◽  
Author(s):  
James G. Tidball
Keyword(s):  
Skeletal Muscle ◽  
Signal Transduction ◽  
Mechanical Activation ◽  
Signaling Pathways ◽  
Mechanical Stimulation ◽  
Muscle Growth ◽  
Mammalian Target Of Rapamycin ◽  
Target Of Rapamycin ◽  
Mechanical Signal ◽  
Igf I

The adaptability of skeletal muscle to changes in the mechanical environment has been well characterized at the tissue and system levels, but the mechanisms through which mechanical signals are transduced to chemical signals that influence muscle growth and metabolism remain largely unidentified. However, several findings have suggested that mechanical signal transduction in muscle may occur through signaling pathways that are shared with insulin-like growth factor (IGF)-I. The involvement of IGF-I-mediated signaling for mechanical signal transduction in muscle was originally suggested by the observations that muscle releases IGF-I on mechanical stimulation, that IGF-I is a potent agent for promoting muscle growth and affecting phenotype, and that IGF-I can function as an autocrine hormone in muscle. Accumulating evidence shows that at least two signaling pathways downstream of IGF-I binding can influence muscle growth and adaptation. Signaling via the calcineurin/nuclear factor of activated T-cell pathway has been shown to have a powerful influence on promoting the slow/type I phenotype in muscle but can also increase muscle mass. Neural stimulation of muscle can activate this pathway, although whether neural activation of the pathway can occur independent of mechanical activation or independent of IGF-I-mediated signaling remains to be explored. Signaling via the Akt/mammalian target of rapamycin pathway can also increase muscle growth, and recent findings show that activation of this pathway can occur as a response to mechanical stimulation applied directly to muscle cells, independent of signals derived from other cells. In addition, mechanical activation of mammalian target of rapamycin, Akt, and other downstream signals is apparently independent of autocrine factors, which suggests that activation of the mechanical pathway occurs independent of muscle-mediated IGF-I release.

scholarly journals Denervation-Induced Activation of the Ubiquitin-Proteasome System Reduces Skeletal Muscle Quantity Not Quality

PLoS ONE ◽  
2016 ◽  
Vol 11 (8) ◽  
pp. e0160839 ◽  
Author(s):  
Cory W. Baumann ◽  
Haiming M. Liu ◽  
LaDora V. Thompson
Keyword(s):  
Skeletal Muscle ◽  
Ubiquitin Proteasome System ◽  
Ubiquitin Proteasome
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