Novel Sarcopenia-related Alterations in Sarcomeric Protein Post-translational Modifications (PTMs) in Skeletal Muscles Identified by Top-down Proteomics.
Mol Cell Proteomics
; 17(1): 134-145, 2018 01.
Article
em En
| MEDLINE
| ID: mdl-29046390
ABSTRACT
Sarcopenia, the age-related loss of skeletal muscle mass and strength, is a significant cause of morbidity in the elderly and is a major burden on health care systems. Unfortunately, the underlying molecular mechanisms in sarcopenia remain poorly understood. Herein, we utilized top-down proteomics to elucidate sarcopenia-related changes in the fast- and slow-twitch skeletal muscles of aging rats with a focus on the sarcomeric proteome, which includes both myofilament and Z-disc proteins-the proteins that constitute the contractile apparatuses. Top-down quantitative proteomics identified significant changes in the post-translational modifications (PTMs) of critical myofilament proteins in the fast-twitch skeletal muscles of aging rats, in accordance with the vulnerability of fast-twitch muscles to sarcopenia. Surprisingly, age-related alterations in the phosphorylation of Cypher isoforms, proteins that localize to the Z-discs in striated muscles, were also noted in the fast-twitch skeletal muscle of aging rats. This represents the first report of changes in the phosphorylation of Z-disc proteins in skeletal muscle during aging. In addition, increased glutathionylation of slow skeletal troponin I, a novel modification that may help protect against oxidative damage, was observed in slow-twitch skeletal muscles. Furthermore, we have identified and characterized novel muscle type-specific proteoforms of myofilament proteins and Z-disc proteins, including a novel isoform of the Z-disc protein Enigma. The finding that the phosphorylation of Z-disc proteins is altered in response to aging in the fast-twitch skeletal muscles of aging rats opens new avenues for the investigation of the role of Z-discs in age-related muscle dysfunction.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sarcômeros
/
Músculo Esquelético
/
Sarcopenia
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Mol Cell Proteomics
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Ano de publicação:
2018
Tipo de documento:
Article