固有免疫调控蛋白PKR串联亲和纯化系统的建立及应用

目的 构建固有免疫调控蛋白--双链RNA(dsRNA)调控的蛋白激酶(PKR)的串联亲和纯化系统(TAP),初步研究PKR蛋白功能,以用于与PKR相互作用的新蛋白的鉴定与功能分析.方法 通过PCR扩增PKR目的基因,克隆至真核表达载体pcTAP-A中.将重组质粒pcTAP-PKR通过脂质体法转染PKR稳定沉默(PKRk...

Establishment and application of a tandem affinity purification system of innate immune regulatory protein PKR

Objective To establish a tandem affinity purification(TAP) system of innate immune-regulatory protein PKR and analyze PKR function, for the future screen and identification of novel PKR-interaction proteins. Methods PKR gene was amplified by PCR, and then cloned into a mammalian expression vector pcTAP-A. Recombinant pcTAP-PKR was transfected into PKR knock-down(PKRkd) HeLa cells by LipofectAMINE 2000,and the PKR overexpressed HeLa cells were harvested for mitogen-activated protein kinases(MAPK) activation analysis. Cell extracts of PKR overexpressed cells were purified using TAP kit and examined by Western blot. Results Cal modulin resin(CBP) and streptavidin resin(SBP) tagged PKR was detected in PKRkd HeLa cells as early as 24 h upon transfection with pcTAP-PKR, and its expression decreased at later time points. The overexpression of PKR was autophosphorylated, and thus involved in the regulation of MAPK actviation. After small-scale TAP kit purification, PKR protein was detectable by Western blot. Conclusion We have successfully established a TAP system that over-expresses functional PKR, providing a useful tool for the future study on the identification of PKR interacting proteins.