Stability of F-box Protein Atrogin-1 is Regulated by p38 Mitogen-activated Protein Kinase Pathway in Cardiac H9c2 Cells
Stability of F-box Protein Atrogin-1 is Regulated by p38 Mitogen-activated Protein Kinase Pathway in Cardiac H9c2 Cells
复制标题
心脏 H9c2 细胞中 F-box 蛋白 Atrogin-1 的稳定性受 p38 丝裂原激活蛋白激酶途径调节
DOI：
10.1159/000329967
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发表时间：
2011-01-01
影响因子：
--
通讯作者：
Li, Hui-Hua
中科院分区：
文献类型：
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作者：
Li, Jun-Jie;Zhang, Tian-Peng;Li, Hui-Hua
背景：Atrogin-1/MAFbx是一种主要的萎缩相关E3泛素连接酶，可作为心脏肥厚的负调节因子。氧化应激通过p38丝裂原活化蛋白激酶（p38 MAPK）诱导atroggin -1 mRNA表达。然而，调控atrogin-1蛋白稳定性的分子机制尚不清楚。方法：按指示用质粒转染293T和心脏H9c2细胞。采用体内外泛素化法和脉冲追踪法检测阿特罗酮-1的泛素化和稳定性。Western blot检测蛋白水平。结果：我们发现atrogin-1在蛋白酶体的泛素介导下被降解。atrogin-1的F-box基序和Skp1-Cul1-Roc1-F-box （SCF）复合物是atrogin-1泛素化和降解所必需的。此外，p38 MAPK信号在调节atrogin-1的泛素化和降解以及血清饥饿诱导的atrogin-1表达和H9c2细胞大小的减小中起着关键作用。结论：这些发现可能定义了通过p38 MAPK信号部分调节atrogin-1稳定性的新机制。
Backgroud: Atrogin-1/MAFbx is a major atrophy-related E3 ubiquitin ligase that functions as a negative regulator of cardiac hypertrophy. The mRNA expression of atrogin-1 is induced by oxidative stress via p38 mitogen-activated protein kinase (p38 MAPK). However, the molecular mechanisms that regulate the stability of atrogin-1 protein remain unclear. Methods: 293T and cardiac H9c2 cells were transfected with plasmids as indicated. The in vivo and in vitro ubiquitination assay and pulse-chase analysis were performed to detect the ubiquitination and stability of atrogin-1. The protein levels were measured by Western blot analysis. Results: We found that atrogin-1 underwent ubiquitin-mediated degradation by proteasome. The F-box motif of atrogin-1 and Skp1-Cul1-Roc1-F-box (SCF) complex are required for ubiquitination and degradation of atrogin-1. Furthermore, p38 MAPK signaling plays critical roles in regulating the ubiquitination and degradation of atrogin-1 as well as serum starvation-induced expression of atrogin-1 and reduction of H9c2 cell size. Conclusion: These findings may define a new mechanism for regulating the stability of atrogin-1 partially by p38 MAPK signaling.