Gene Expression of Muscle-Specific Ubiquitin Ligase, Atrogin-1/MAFbx, Positively Correlates with Skeletal Muscle Proteolysis in Food-Deprived Broiler Chickens
Gene Expression of Muscle-Specific Ubiquitin Ligase, Atrogin-1/MAFbx, Positively Correlates with Skeletal Muscle Proteolysis in Food-Deprived Broiler Chickens
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DOI：
10.2141/jpsa.010093
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发表时间：
2011-04-01
影响因子：
1.5
通讯作者：
Hayashi, Kunioki
中科院分区：
文献类型：
--
作者：
Ohtsuka, Akira;Kawatomi, Noriko;Hayashi, Kunioki
研究了禁食肉鸡骨骼肌蛋白水解与肌特异性泛素连接酶atrogin-1/MAFbx mRNA表达之间的关系。在响应于食物剥夺24和48小时，体重和肌肉重量下降的时间依赖性的方式。肌肉游离N-tau-甲基组氨酸含量，肌原纤维蛋白水解的指数，是1.8倍和2.5倍以上的喂养控制后24和48小时的食物剥夺，分别。atrogin-1/MAFbx的基因表达急剧增加，以时间依赖性的方式响应于食物剥夺。在48小时的食物剥夺，atrogin-1/MAFbx mRNA表达水平的诱导升高高达20倍以上的喂养对照。相反，20 S蛋白酶体C1和C2亚基的mRNA表达水平随着时间的推移而下降。泛素mRNA表达的变化无显著性差异。atrogin-1/MAFbx的表达与肌肉质量呈高度显著的线性负相关（r（2）=0.754，P < 0.001），与肌肉游离N-tau-甲基组氨酸含量呈高度显著的线性正相关（r（2）= 0.784，P < 0.001）。这些结果表明，atrogin-1/MAFbx在肉鸡肌肉蛋白质降解过程中起着重要作用，其基因表达水平可作为肌肉蛋白质降解的可靠指标。
A relationship between skeletal muscle proteolysis and mRNA expression of atrogin-1/MAFbx, a muscle-specific ubiquitin ligase, was examined in food-deprived broiler chickens. In response to food deprivation for 24 and 48 h, body and muscle weights decreased in a time-dependent manner. Muscle free N-tau-methylhistidine content, an index of myofibrillar proteolysis, was 1.8-fold and 2.5-fold greater than that of fed controls following 24 and 48 h of food deprivation, respectively. Gene expression of atrogin-1/MAFbx drastically increased in response to food deprivation in a time-dependent manner. At 48 h of food deprivation, the induction of atrogin-1/MAFbx mRNA expression level elevated up to 20-fold greater than that of fed controls. By contrast, mRNA expression levels of 20S proteasome Cl and C2 subunits tended to decrease with time. No significant difference was seen in the change of ubiquitin mRNA expression. A highly significant linear negative relationship (r(2)=0.754, P < 0.001) was found between atrogin-1/MAFbx expression and muscle mass, while a highly significant linear positive relationship (r(2) = 0.784, P < 0.001) was found between atrogin-1/MAFbx expression and muscle free N-tau-methylhistidine content. These results indicate that atrogin-1/MAFbx plays a critical role in the development of muscle proteolysis and its gene expression is a reliable index of muscle proteolysis in broiler chickens.