Effects of 18-glycyrrhetinic acid on serine 368 phosphorylation of connexin43 in rat neonatal cardiomyocytes
Effects of 18-glycyrrhetinic acid on serine 368 phosphorylation of connexin43 in rat neonatal cardiomyocytes
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DOI：
10.1016/j.cellbi.2008.08.007
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发表时间：
2008-11-01
影响因子：
3.9
通讯作者：
Wu, Jiahn-Chun
中科院分区：
文献类型：
--
作者：
Liang, Jyun-Yan;Wang, Seu-Mei;Wu, Jiahn-Chun
18β - 甘草次酸（18β - GA）调节连接蛋白43（Cx43）的丝氨酸/苏氨酸去磷酸化。在此使用磷酸化特异性抗体，通过免疫荧光显微镜和免疫印迹分析来确定18β - GA对培养的大鼠新生心肌细胞中丝氨酸368磷酸化的Cx43（pSer368Cx43）的影响。18β - GA导致pSer368Cx43水平呈时间依赖性增加，并诱导缝隙连接解体，这表现为pSer368Cx43免疫染色在细胞 - 细胞接触区域从大的聚集体变为分散的点状。18β - GA还诱导丝氨酸729磷酸化的PKC ε（PKC ε的活性形式）水平呈时间依赖性增加。PKC抑制剂白屈菜红碱消除了18β - GA诱导的pSer368Cx43水平的增加以及pSer368Cx43染色模式的改变。此外，18β - GA增加了Cx43与PKC ε的共免疫沉淀。然而，蛋白磷酸酶1型和2A抑制剂花萼海绵诱癌素A共同处理抑制了18β - GA诱导的pSer368Cx43水平的增加以及Cx43与PKC ε结合的增加。我们得出结论，18β - GA通过PKC ε诱导Cx43的Ser368磷酸化。（C）2008国际细胞生物学联合会。由爱思唯尔有限公司出版。保留所有权利。
18 beta-Glycyrrhetinic acid (18 beta-GA) regulates serine/threonine dephosphorylation of connexin43 (Cx43). Phospho-specific antibodies were used here to determine the effect of 18 beta-GA on serine 368-phosphorylated Cx43 (pSer368Cx43) in cultured rat neonatal cardiomyocytes by immunofluorescence microscopy and immunoblot analyses. 18 beta-GA caused a time-dependent increase in pSer368Cx43 levels and induced gap junction disassembly, shown by a change in pSer368Cx43 immunostaining from large aggregates to dispersed punctates at cell-cell contact areas. 18 beta-GA also induced a time-dependent increase in the levels of serine 729-phosphorylated PKC epsilon, the active form of PKC epsilon. The 18 beta-GA-induced increase in pSer368Cx43 levels and changes in pSer368Cx43 staining pattern were abolished by the PKC inhibitor, chelerythrine. Furthermore, 18 beta-GA increased the co-immunoprecipitation of Cx43 with PKC epsilon. However, the 18 beta-GA-induced increase in pSer368Cx43 levels and increased association of Cx43 with PKC epsilon were inhibited by co-treatment with the protein phosphatase type 1 and type 2A inhibitor, calyculin A. We conclude that 18 beta-GA induces Ser368 phosphorylation of Cx43 via PKC epsilon. (C) 2008 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.