Dept. of Physiology, School of Medicine, Shenzhen University, Shenzhen 518060, PR China.
FEBS Lett. 2012 Oct 19;586(20):3674-80. doi: 10.1016/j.febslet.2012.08.025. Epub 2012 Sep 6.
Syntabulin is a microtubule-associated protein that mediates anterograde transport of vesicles to neuronal processes. Here, we found that syntabulin was expressed in mouse pancreas and insulin-secreting β-cells, and that it partially co-localized with microtubule and insulin-containing granules. The association of syntabulin with these organelles increased upon glucose stimulation. Knock-down of syntabulin by shRNA reduced both basal and glucose-stimulated insulin secretion, and diminished cAMP-Epac2 and cAMP-PKA potentiated insulin secretion. Additionally, syntabulin was preferentially phosphorylated by the Epac2 agonist 8-pCPT-2'-O-Me-cAMP, suggesting that syntabulin could be a novel effector of Epac2 and play a critical role in cAMP-enhanced insulin secretion.
突触结合蛋白是一种微管相关蛋白，介导囊泡向神经元突起的正向运输。在这里，我们发现突触结合蛋白在小鼠胰腺和胰岛素分泌β细胞中表达，并且它与微管和含有胰岛素的颗粒部分共定位。葡萄糖刺激后，突触结合蛋白与这些细胞器的结合增加。shRNA 敲低突触结合蛋白减少了基础和葡萄糖刺激的胰岛素分泌，并减弱了 cAMP-Epac2 和 cAMP-PKA 增强的胰岛素分泌。此外，Epac2 激动剂 8-pCPT-2'-O-Me-cAMP 优先磷酸化突触结合蛋白，表明突触结合蛋白可能是 Epac2 的一种新型效应物，在 cAMP 增强的胰岛素分泌中发挥关键作用。
