Mapping of O-linked beta-N-acetylglucosamine modification sites in key contractile proteins of rat skeletal muscle.
Proteomics
; 9(8): 2139-48, 2009 Apr.
Article
em En
| MEDLINE
| ID: mdl-19322778
ABSTRACT
O-linked beta-N-acetylglucosamine (O-GlcNAc) is a widespread modification of serine/threonine residues of nucleocytoplasmic proteins. Recently, several key contractile proteins in rat skeletal muscle (i.e., myosin heavy and light chains and actin) were identified as O-GlcNAc modified. Moreover, it was demonstrated that O-GlcNAc moieties involved in contractile protein interactions could modulate Ca(2+) activation parameters of contraction. In order to better understand how O-GlcNAc can modulate the contractile activity of muscle fibers, we decided to identify the sites of O-GlcNAc modification in purified contractile protein homogenates. Using an MS-based method that relies on mild beta-elimination followed by Michael addition of DTT (BEMAD), we determined the localization of one O-GlcNAc site in the subdomain four of actin and four O-GlcNAc sites in the light meromyosin region of myosin heavy chains (MHC). According to previous reports concerning the role of these regions, our data suggest that O-GlcNAc sites might modulate the actin-tropomyosin interaction, and be involved in MHC polymerization or interactions between MHC and other contractile proteins. Thus, the results suggest that this PTM might be involved in protein-protein interactions but could also modulate the contractile properties of skeletal muscle.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Acetilglucosamina
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Processamento de Proteína Pós-Traducional
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Músculo Esquelético
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Proteínas Musculares
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article