热休克蛋白70通过增强载脂蛋白B mRNA编辑酶催化多肽样蛋白3B的脱氨酶活性抑制乙型肝炎病毒复制

Heat shock protein 70 inhibits hepatitis B virus replication by enhancing the deaminase activity of apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3B

目的研究热休克蛋白70(heat shock protein 70,HSP70)在载脂蛋白B mRNA编辑酶催化多肽样蛋白3B(apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3B,APOBEC3B)抑制乙型肝炎病毒(hepatitis B virus,HBV)复制过程中的作用及机制。方法通过免疫共沉淀(co-immunopreciptation,Co-IP)和GST pull-down试验研究HSP70与APOBEC3B的相互作用。干扰HSP70、过表达HSP70或使用HSP70抑制剂VER155008处理肝细胞后,Southern blot或real-time PCR检测APOBEC3B抗病毒作用的改变;差异DNA变性PCR(differential DNA denaturation PCR,3D-PCR)和克隆测序检测APOBEC3B脱氨酶活性的改变。结果HSP70能与APOBEC3B相结合,过表达HSP70能增强APOBEC3B的脱氨酶活性和抗HBV功能。相反,干扰HSP70或使用HSP70抑制剂VER155008后,APOBEC3B脱氨酶活性和抗HBV功能均减弱。结论HSP70通过增强APOBEC3B的脱氨酶活性增强其抗病毒功能。

Objective To study the role and mechanism of heat shock protein 70(HSP70)in apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3B(APOBEC3B)-mediated inhibition of hepatitis B virus(HBV)replication.Methods The interaction between HSP70 and APOBEC3B was analyzed by co-immunopreciptation(Co-IP)and GST pull-down.After treating Huh7 cells with siHSP70 or HSP70 inhibitor VER155008 or overexpressing HSP70 in Huh7 cells,changes in the antiviral effect of APOBEC3B were detected by Southern blot and real-time PCR;the deaminase activity of APOBEC3B was tested by differential DNA denaturation PCR(3D-PCR)and clone sequencing.Results HSP70 could bind to APOBEC3B.Overexpression of HSP70 promoted the deaminase activity and anti-HBV activity of APOBEC3B.On the contrary,knockdown of HSP70 or using HSP70 inhibitor VER155008 would attenuate the deaminase activity and anti-HBV activity of APOBEC3B.Conclusions HSP70 could promote the anti-HBV activity of APOBEC3B by enhancing the deaminase activity of APOBEC3B.