口蹄疫病毒3C蛋白酶切割宿主蛋白PCBP2  

Foot-and-mouth disease virus 3C protease cleaves RNA-binding protein of poly(C) binding protein 2

作　　者：杨春梅[1,2] 黄丽[2] 王海伟[2] 于会彬[2] 李一经[3] 蔡雪辉[2] 于力[2] 唐丽杰[1,3] 翁长江[2] 

机构地区：[1]东北农业大学生命科学学院,黑龙江哈尔滨150030 [2]中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/动物病原监测与流行病学研究创新团队,黑龙江哈尔滨150001 [3]东北农业大学动物医学学院,黑龙江哈尔滨150030

出　　处：《中国预防兽医学报》2014年第6期419-422,共4页Chinese Journal of Preventive Veterinary Medicine

基　　金：国家自然科学基金(31300139);中国农业科学院基本科研业务费预算增量项目(2013ZL034)

摘　　要：口蹄疫病毒(FMDV)3C蛋白酶(3Cpro)能够通过切割翻译起始因子4G(eIF4G)抑制宿主蛋白合成,而宿主多聚胞嘧啶结合蛋白2(PCBP2)的主要功能之一是参与蛋白质合成。本研究通过western blot检测显示,在FMDV感染BHK-21细胞中PCBP2蛋白水平显著降低。为鉴定FMDV 3Cpro是否具有切割PCBP2蛋白的功能,本研究采用免疫共沉淀试验和激光共聚焦检测显示,FMDV 3Cpro和PCBP2在细胞内存在相互作用,并且共定位于细胞质中。进一步研究显示,FMDV 3Cpro能够切割PCBP2,而且具有剂量依赖性。此外,FMDV 3Cpro活性位点突变(H46Y)试验结果表明,FMDV 3Cpro的蛋白酶活性是切割蛋白PCBP2所必需的。FMDV 3Cpro切割PCBP2靶位点序列的鉴定及FMDV 3Cpro切割PCBP2的生物学意义有待深入研究。Host protein synthesis is inhibited in foot-and-mouth disease virus （FMDV） infected host cells by cleaving the translation initiation factor 4G （elF4G） via FMDV 3C proteinase （3Cpro）. Then the RNA-binding protein of poly （C） binding protein 2 （PCBP2） was also involved in protein synthesis. In this study, it was found that the protein level of PCBP2 was significantly reduction in FMDV infected BHK-21 cells. To identify whether PCBP2 was cleaved by FMDV 3Cpro to inhibit the host protein synthesis, the co-immunoprecipitation and confocal laser scan microscopy assay results demonstrated that FMDV 3Cpro interacted and colocalized with host protein PCBP2. In addition, PCBP2 was cleaved by FMDV 3Cpro in a dose-dependent manner. Further test showed that the H46 was the crucial amino acid for FMDV 3Cpro activity required for cleavage of PCBP2, which was proved by H46y point mutation in the activity domain of FMDV 3Cpro. However, the target cleavage sites in PCBP2 need to be further identified.

关 键 词：口蹄疫病毒 3C蛋白酶 PCBP2 切割 

分 类 号：S852.65[农业科学—基础兽医学]