Present address: School of Medicine, Fu-Jen Catholic University, Taipei 24205, Taiwan.
Effects of 18-glycyrrhetinic acid on serine 368 phosphorylation of connexin43 in rat neonatal cardiomyocytes
Article first published online: 2 JAN 2013
© The Author(s) Journal compilation © 2008 International Federation for Cell Biology
Cell Biology International
Volume 32, Issue 11, pages 1371–1379, November 2008
How to Cite
Liang, J.-Y., Wang, S.-M., Chung, T.-H., Yang, S.-H. and Wu, J.-C. (2008), Effects of 18-glycyrrhetinic acid on serine 368 phosphorylation of connexin43 in rat neonatal cardiomyocytes. Cell Biology International, 32: 1371–1379. doi: 10.1016/j.cellbi.2008.08.007
- Issue published online: 2 JAN 2013
- Article first published online: 2 JAN 2013
- Received 27 September 2007; revised 30 May 2008; accepted 12 August 2008
- 18β-Glycyrrhetinic acid;
- Gap junction;
- Protein kinase C;
18β-Glycyrrhetinic acid (18β-GA) regulates serine/threonine dephosphorylation of connexin43 (Cx43). Phospho-specific antibodies were used here to determine the effect of 18β-GA on serine 368-phosphorylated Cx43 (pSer368Cx43) in cultured rat neonatal cardiomyocytes by immunofluorescence microscopy and immunoblot analyses. 18β-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. 18β-GA also induced a time-dependent increase in the levels of serine 729-phosphorylated PKCɛ, the active form of PKCɛ. The 18β-GA-induced increase in pSer368Cx43 levels and changes in pSer368Cx43 staining pattern were abolished by the PKC inhibitor, chelerythrine. Furthermore, 18β-GA increased the co-immunoprecipitation of Cx43 with PKCɛ. However, the 18β-GA-induced increase in pSer368Cx43 levels and increased association of Cx43 with PKCɛ were inhibited by co-treatment with the protein phosphatase type 1 and type 2A inhibitor, calyculin A. We conclude that 18β-GA induces Ser368 phosphorylation of Cx43 via PKCɛ.