胰岛素样生长因子结合蛋白-3与甲状腺激素受体α1的相互作用及其对甲状腺激素应答性基因转录的调节  

Insulin-like Growth Factor Binding Protein-3 Interacts with the Thyroid Hormone Receptor α1 and Modulates Transcription of Thyroid Hormone Responsive Gene

作　　者：裘佳[1] 马晓骊[1] 王欣[1] 陈虹[1] 黄秉仁[1] 

机构地区：[1]中国医学科学院北京协和医学院基础医学研究所医学分子生物学国家重点实验室,北京100005

出　　处：《中国医学科学院学报》2011年第2期156-161,222,共7页Acta Academiae Medicinae Sinicae

摘　　要：目的探讨胰岛素样生长因子结合蛋白-3(IGFBP-3)与甲状腺激素受体α1(TRα1)之间的相互作用,及其对甲状腺激素应答性基因转录作用的调节。方法采用谷胱甘肽-S-转移酶拉下实验、免疫共沉淀以及荧光共振能量转移实验检测IGFBP-3与TRα1之间的相互作用;激光共聚焦显微镜观察两种蛋白在细胞中的分布;采用双萤光素酶实验检测过表达IGFBP-3对甲状腺素T3激活的生长激素启动子的影响。结果谷胱甘肽-S-转移酶拉下实验、免疫共沉淀以及荧光共振能量转移实验结果证明IGFBP-3与TRα1在体内和体外都可以相互作用,激光共聚焦显微镜观察IGFBP-3和TRα1可以共定位于HEK-293细胞的细胞核。通过双萤光素酶实验检测到过表达IGFBP-3可以抑制甲状腺激素对生长激素启动子的激活作用(P<0.01)。结论 IGFBP-3通过与TRα1相互作用抑制甲状腺激素应答性基因的转录,为IG-FBP-3在核内发挥胰岛素样生长因子非依赖的作用提供了新的实验依据。Objective To study the interaction between insulin-like growth factor binding protein-3（IGFBP-3） and thyroid hormone receptor α1（TRα1） and the modulatory effect of IGFBP-3 on transcription of the thyroid hormone responsive gene.Methods The interaction between IGFBP-3 and TRα1 was detected with glutathione-S-transferase pull-down method,co-immunoprecipitation,fluorescence resonance energy transfer test.The cellular distribution of these two proteins was observed by confocal laser scanning microscopy.The effect of IGFBP-3 on the growth hormone promoter activity stimulated by triiodothyronine（T3） was determined by dual-luciferase reporter assay.Results IGFBP-3 interacted with TRα1 both in vivo and in vitro.IGFBP-3 and TRα1 were shown to co-localize in the nucleus of HEK-293 cells.The overexpressed IGFBP-3 inhibited the growth hormone promoter activity stimulated by T3（P0.01）.Conclusions IGFBP-3 interacts with TRα1 and inhibits T3 responsive gene transcription.This finding further confirms the insulin-like growth factor-independent role of IGFBP-3 in the nucleus.

关 键 词：胰岛素样生长因子结合蛋白-3 甲状腺激素受体α1 三碘甲状腺原氨酸 生长激素启动子 

分 类 号：Q571[生物学—生物化学]