CAJ | 학술논문

目的探讨干扰素α(IFN-α)调控维甲酸诱导基因G(RIG-G)表达调控的分子机制.方法采用Western blot方法检测急性早幼粒白血病细胞系NB4经IFN-α处理后信号传导和转录活化因子1(STAT1)、p-STAT1和RIG-G蛋白的表达变化.采用细胞转染、报告基因实验、免疫共沉淀实验和染色质免疫沉淀实验等技术,研究STAT1缺失的U3A细胞中,STAT1、STAT2和IFN调节因子9(IRF-9)在IFN-α调控RIG-G基因表达中的作用及其机制.结果在 U3A 细胞中,只有当STAT2和IRF-9共同转染时,RIG-G启动子荧光素酶报告基因的表达活性才明显升高,约为空载对照组的8倍.在无IFN-α作用时,野生型或突变型STAT2与IRF-9共同转染U3A细胞可产生相似的效应;但IFN-α能进一步增强野生型STAT2与IRF-9的转录激活作用,约为未加IFN-α时的6倍,而对突变型STAT2无效.STAT2能与IRF-9相互作用,并能与RIG-G基因的启动子结合.结论 STAT2和IRF-9能以不依赖于STAT1的形式发生相互作用,所形成的复合物是介导IFN-α调控RIG-G基因表达的关键性转录因子,这是一种有别于经典JAK-STAT途径的新的干扰素信号转导方式.
목적 탐토간우소α(IFN-α)조공유갑산유도기인G(RIG-G)표체조공적분자궤제.방법 채용Western blot방법검측급성조유립백혈병세포계NB4경IFN-α처리후신호전도화전록활화인자1(STAT1)、p-STAT1화RIG-G단백적표체변화.채용세포전염、보고기인실험、면역공침정실험화염색질면역침정실험등기술,연구STAT1결실적U3A세포중,STAT1、STAT2화IFN조절인자9(IRF-9)재IFN-α조공RIG-G기인표체중적작용급기궤제.결과 재 U3A 세포중,지유당STAT2화IRF-9공동전염시,RIG-G계동자형광소매보고기인적표체활성재명현승고,약위공재대조조적8배.재무IFN-α작용시,야생형혹돌변형STAT2여IRF-9공동전염U3A세포가산생상사적효응;단IFN-α능진일보증강야생형STAT2여IRF-9적전록격활작용,약위미가IFN-α시적6배,이대돌변형STAT2무효.STAT2능여IRF-9상호작용,병능여RIG-G기인적계동자결합.결론 STAT2화IRF-9능이불의뢰우STAT1적형식발생상호작용,소형성적복합물시개도IFN-α조공RIG-G기인표체적관건성전록인자,저시일충유별우경전JAK-STAT도경적신적간우소신호전도방식.
Objective To investigate the molecular mechanisms by which IFN-α regulated retinoic acid-induced gene G (RIG-G) expression. Methods The expression of STAT1, p-STAT1 and RIG-G in IFN-α-treated NB4 cells was detected by Westem blot. The roles of STAT1, STAT2 and IRF-9 in IFN-α-induced RIG-G expression were analyzed in STAT1-null U3A cells by cell transfection, reporter gene assay, co-immunoprecipitation and chromatin immunoprecipitaion. Results In U3A cells, only when STAT2 and IRF-9 were co-transfected, the luciferase activities of RIG-G promoter-containing reporter gene could be highly increased about 8-fold compared with that in the control group. Moreover, in the absence of IFN-α,similar effects were observed in either IRF-9 co-transfected with wild type or mutant form of STAT2, whereas IFN-α could increase the transactivation activity of wild type STAT2 and IRF-9 by 6-fold compared with that without IFN-α, but had no effect on mutant STAT2. In addition, STAT2 could interact with IRF-9 and bind to the RIG-G promoter. Conclusion STAT2 may interact with IRF-9 in a STAT1-independent manner. The complex STAT2/IRF-9 is the key factor mediating the expression of RIG-G gene regulated by IFN-α. This is a novel signal transduction cascade for IFN which is different from the classical JAK-STAT pathway.