Xu Yizhou, Wang Ningfu, Ling Feng, Li Peizhang, Gao Yan
Department of Cardiology, Hangzhou the First People's Hospital, 261 Wansha Road, Hangzhou 310006, China.
Biochem Biophys Res Commun. 2009 Jan 2;378(1):95-8. doi: 10.1016/j.bbrc.2008.11.026. Epub 2008 Nov 21.
Adiponectin is an adipose tissue derived hormone with anti-diabetic and insulin-sensitizing properties. Two adiponectin receptors, AdipoR1 and AdipoR2, have recently been identified, yet the signaling pathways triggered through adiponectin receptors remain to be elucidated. Using a yeast two-hybrid screen, we identified an adaptor protein, receptor for activated protein kinase C1 (RACK1), as an interacting partner of human AdipoR1. RACK1 was confirmed to interact with AdipoR1 by co-immunoprecipitation and co-localization analysis in mammalian cells. The interaction was enhanced by adiponectin stimulation. In addition, the knockdown of RACK1 by RNA interference inhibited adiponectin-stimulated glucose uptake in HepG2 cells. These results suggest that RACK1 may act as a key bridging factor in adiponectin signaling transduction through interacting with AdipoR1.
脂联素是一种源自脂肪组织的激素，具有抗糖尿病和胰岛素增敏特性。最近已鉴定出两种脂联素受体，即脂联素受体1（AdipoR1）和脂联素受体2（AdipoR2），然而通过脂联素受体触发的信号通路仍有待阐明。利用酵母双杂交筛选，我们鉴定出一种衔接蛋白，即活化蛋白激酶C1受体（RACK1），作为人AdipoR1的相互作用伴侣。通过共免疫沉淀和哺乳动物细胞中的共定位分析，证实RACK1与AdipoR1相互作用。脂联素刺激可增强这种相互作用。此外，通过RNA干扰敲低RACK1可抑制脂联素刺激的HepG2细胞中的葡萄糖摄取。这些结果表明，RACK1可能通过与AdipoR1相互作用，在脂联素信号转导中充当关键的桥梁因子。
