cAMP-PKA参与辐射诱导p27^(Kip1)蛋白的表达调控  

Involvement of cAMP-PKA in regulation of p27^(Kip1) expression induced by ionizing radiation

作　　者：张枫[1] 孟祥兵[1] 宋宜[1] 梅柱中[1] 董燕[1] 刘斌[1] 孙志贤[1] 

机构地区：[1]北京放射医学研究所,100850

出　　处：《中华放射医学与防护杂志》2004年第5期393-395,共3页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金资助项目 ( 3 0 0 70 2 3 9;3 0 170 2 91)

摘　　要：目的　研究电离辐射反应中p2 7Kip1 表达调控机理。方法　将p2 7Kip1 蛋白编码全长基因克隆导入原核表达载体pGEX4T 2 ,经异丙基硫代 β D 半乳糖苷 (IPTG)诱导表达后再经GST Sephrose 4B柱亲和层析、纯化 ,获取的GST p2 7Kip1 融合蛋白作为磷酸化底物 ,并进行体外磷酸化检测。结果　PKA具有磷酸化p2 7Kip1 蛋白的功能 ,该反应能被PKA的特异性抑制剂H89所抑制 ;照射后细胞内源性的PKA对p2 7Kip1 的磷酸化程度减弱。结论　cAMP PKA在电离辐射诱导细胞周期检查点蛋白p2 7Kip1Objective\ To study the mechanism of p27^(Kip1) down-regulation induced by ionizing radiation(IR). Methods\ The cDNA of p27^(Kip1) was cloned into prokaryotic expression vector pGEX4T-2.The recombinant protein GST-p27^(Kip1) was induced by isopropyl-β-D-thiroglactoside (IPTG) and purified by GST-Sepharose 4B affinity chromatography. Results\ GST-p27^(Kip1) was phosphorylated by PKAc,and this in vitro phosphorylation could be inhibited by PKA specific inhibitor H89.Phosphorylation level of GST-p27^(Kip1) decreased after IR,when treated with immunoprecipited endogenous PKA. Conclusion\ The results suggest that cAMP-PKA plays a critical role in down-regulation of p27^(Kip1) during IR.\;

关 键 词：P27^KIP1蛋白 PKA 磷酸化 电离辐射诱导 表达调控 GSTS 特异性抑制剂 AMP IPTG 诱导表达 

分 类 号：R346[医药卫生—基础医学]