Department of Orthopaedics, University of Maryland, School of Medicine, Baltimore, MD, USA.
BMC Biochem. 2010 Mar 25;11:14. doi: 10.1186/1471-2091-11-14.
We have recently demonstrated that modulation of the gap junction protein, connexin43, can affect the response of osteoblasts to fibroblast growth factor 2 in a protein kinase C-delta-dependent manner. Others have shown that the C-terminal tail of connexin43 serves as a docking platform for signaling complexes. It is unknown whether protein kinase C-delta can physically interact with connexin43.
In the present study, we investigate by immunofluorescent co-detection and biochemical examination the interaction between Cx43 and protein kinase C-delta. We establish that protein kinase C-delta physically interacts with connexin43 during fibroblast growth factor 2 signaling, and that protein kinase C delta preferentially co-precipitates phosphorylated connexin43. Further, we show by pull down assay that protein kinase C-delta associates with the C-terminal tail of connexin43.
Connexin43 can serve as a direct docking platform for the recruitment of protein kinase C-delta in order to affect fibroblast growth factor 2 signaling in osteoblasts. These data expand the list of signal molecules that assemble on the connexin43 C-terminal tail and provide a critical context to understand how gap junctions modify signal transduction cascades in order to impact cell function.
我们最近证明，连接蛋白 43 的缝隙连接蛋白的调节可以以蛋白激酶 C-δ依赖性的方式影响成骨细胞对成纤维细胞生长因子 2 的反应。其他人已经表明，连接蛋白 43 的 C 末端尾部充当信号复合物的对接平台。目前尚不清楚蛋白激酶 C-δ是否可以与连接蛋白 43 发生物理相互作用。
在本研究中，我们通过免疫荧光共检测和生化检查研究了 Cx43 和蛋白激酶 C-δ之间的相互作用。我们确定在成纤维细胞生长因子 2 信号转导过程中，蛋白激酶 C-δ与连接蛋白 43 发生物理相互作用，并且蛋白激酶 C-δ优先共沉淀磷酸化的连接蛋白 43。此外，我们通过下拉实验表明，蛋白激酶 C-δ与连接蛋白 43 的 C 末端尾部相关联。
连接蛋白 43 可以作为募集蛋白激酶 C-δ的直接对接平台，以影响成骨细胞中的成纤维细胞生长因子 2 信号转导。这些数据扩展了在连接蛋白 43 C 末端尾部组装的信号分子列表，并提供了一个关键的背景，以了解间隙连接如何修饰信号转导级联以影响细胞功能。
