Cx43 phosphorylation on S279/282 and intercellular communication are regulated by IP3/IP3 receptor signaling

Cell Communication and Signaling

Research

Junqi He¹  Yuanyuan Zheng²  Dali Luo²  Xinxin Yan²  Chao Zhang²  Man Kang²  Qingli Meng²  Chen Li³  Na Lin⁴  Yang Ou⁴  Jianxin Deng⁴ 

[1] Department of Biochemistry, Capital Medical University, 100069, Beijing, China;Department of Pharmacology, Capital Medical University, 100069, Beijing, China;Department of Pharmacology, Capital Medical University, 100069, Beijing, China;National Institute for Radiological Protection, China CDC, 100088, Beijing, China;Institute of Molecular Medicine, Peking University, 100871, Beijing, China;

关键词: Inositol 1,4,5-trisphosphate receptor;    Gap junction;    Connexin 43;    Serine 279/282 phosphorylation;    Intercellular communication;    Ventricular myocyte;   

DOI  :  10.1186/s12964-014-0058-6

 received in 2013-12-02, accepted in 2014-09-11,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundInositol 1,4,5-trisphosphate receptor (IP3R) plays a pivotal role in the Ca2+ release process in a variety of cell types. Additionally, IP3R is distributed in ventricular intercalated discs, but its function(s) in this particular site remains unknown. Connexin (Cx43), the predominant gap junction (GJ) protein in ventricular myocardium, is linked to several signaling pathways that regulate Cx43 properties by (de)phosphorylation on multiple residues. Here, we investigated the regulatory role of IP3R in cell-cell communication and the mechanism(s) underlying this effect.ResultsIn neonatal rat and adult mouse ventricular myocytes IP3R co-localized and co-immunoprecipitated with Cx43 in GJ plaques detected by immunostaining and western blot assays. Blocking IP3R with antagonists or silencing pan-IP3R expression with shRNA hindered the 6-carboxyfluorescein (6-CFDA) diffusion through GJs and desynchronized Ca2+ transients among confluent neonatal myocytes in culture, whereas stimulation of IP3R with IP3 ester or ATP exerted the opposite effect. Likewise, 6-CFDA propagation through GJs was modulated by IP3R activation or inhibition in cell pairs of isolated adult cardiomyocytes. Furthermore, IP3R activation or IP3R suppression promoted or suppressed, respectively, Cx43 phosphorylation on S279/282. Site-directed mutagenesis indicated that expression of a mutant Cx43-S282A (alanine) inhibited S279/282 phosphorylation and GJ permeability, while the S279A mutant showed the opposite effect in ventricular myocytes. Expression of these mutants in HEK293 cells revealed that cells with a dual S279/282 mutation failed to express exogenous Cx43, whereas cells with a single S279 or S282 mutation displayed Cx43 overexpression with increased phosphorylation of S279/282 and promotion of intercellular communication.ConclusionsThese results demonstrated, for the first time, that IP3R physically interacts with Cx43 and participates in the regulation of Cx43 phosphorylation on S279/282, thereby affecting GJ intercellular communication in ventricular myocytes.

【 授权许可】

Unknown   
© Kang et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.