黏病毒抗性蛋白A(myxovirus resistance protein A,MxA)是由干扰素诱导的具有重要抗乙肝病毒(hepatitis B virus,HBV)功能的蛋白质,我们前期工作发现,MxA主要依赖其中心互作结构域(central interactive domain,CID)与病毒直接相互作用...黏病毒抗性蛋白A(myxovirus resistance protein A,MxA)是由干扰素诱导的具有重要抗乙肝病毒(hepatitis B virus,HBV)功能的蛋白质,我们前期工作发现,MxA主要依赖其中心互作结构域(central interactive domain,CID)与病毒直接相互作用发挥功能,但其具体的抗病毒功能区以及功能区是否具有独立的抗病毒活性仍不清楚。本研究拟鉴定MxA蛋白上的抗乙肝病毒活性肽。首先从全长MxA构建缺失突变体ΔCID和截短体CID,以HepG2.2.15细胞为病毒模型,分别转染空载质粒、MxA、ΔCID和CID,免疫荧光法检测转染效率,Western印迹法检测质粒表达,酶联免疫法测定细胞培养液中HBsAg、HBeAg的量及荧光定量PCR法测定乙肝病毒DNA的量,评估CID段的抗乙肝病毒活性。根据CID段的晶体结构,缩短肽段长度,构建α1、α2、α3等9段肽段质粒,鉴定各段的抗乙肝病毒活性和细胞毒性(MTT法)。运用计算生物学手段——分子对接法预测MxA蛋白与病毒相互作用的模式和位点。结果显示,ΔCID、CID和9段肽段质粒的序列及表达正确,9段肽段的表达量未见显著性差异,无显著的细胞毒性。CID组和黏病毒抗性蛋白A组较对照组乙肝病毒的复制水平显著降低,CID组细胞上清中HBsAg、HBeAg及乙肝病毒DNA的量分别减少了55.57%±8.48%、68.37%±6.24%、66.67%±6.40%,P<0.01;MxA组的3个指标分别减少了61.63%±3.11%、70.77%±7.25%、73.73%±6.18%,P<0.01;ΔCID组较对照组无明显变化。9段肽段中α1组较对照组HBsAg、HBeAg及乙肝病毒DNA的量有显著下降,分别减少了48.33%±1.70%、70.67%±3.30%、68.95%±2.55%,P<0.001,表明α1对乙肝病毒具有强抑制活性。分子对接的结果显示,384~408位氨基酸是MxA蛋白与病毒互作的关键位点,该区域落在α1肽段上,验证了α1是MxA蛋白抗乙肝病毒及与乙肝病毒相互作用中的关键区段。本研究筛选并鉴定出人干扰素诱导蛋白MxA上最有效的抗乙肝病毒活性肽α1,研究结果为抗乙肝病毒多肽类新药的研发奠定了基础。展开更多
The human myxovirus resistance 2(Mx2/Mx B)protein,a member of interferon(IFN)-inducible dynamin-like large GTPases,restricts a number of virus infections.Inhibition of these viruses occurs at poorly-defined steps afte...The human myxovirus resistance 2(Mx2/Mx B)protein,a member of interferon(IFN)-inducible dynamin-like large GTPases,restricts a number of virus infections.Inhibition of these viruses occurs at poorly-defined steps after viral entry and has a common requirement for Mx B oligomerization.However,the GTPase activity is essential for the anti-viral effects of Mx B against herpesviruses and HBV but not HIV-1.To understand the role of Mx B GTPase activity,including GTP binding and GTP hydrolysis,in restriction of HIV-1 infection,we genetically separated these two functions and evaluated their contributions to restriction.We found that both the GTP binding and hydrolysis function of Mx B involved in the restriction of HIV-1 replication.The GTPase activity of Mx B contributed to its nuclear location,interaction with nucleoporins(NUPs)and HIV-1 capsids.Furthermore,Mx B disrupted the association between NUPs and HIV-1 cores dependently upon its GTPase activity.The function of GTPase activity was therefore multi-faceted,led to fundamentally distinct mechanisms employed by wild-type Mx B and GTPase activity defective Mx B mutations to restrict HIV-1 replication.展开更多
文摘黏病毒抗性蛋白A(myxovirus resistance protein A,MxA)是由干扰素诱导的具有重要抗乙肝病毒(hepatitis B virus,HBV)功能的蛋白质,我们前期工作发现,MxA主要依赖其中心互作结构域(central interactive domain,CID)与病毒直接相互作用发挥功能,但其具体的抗病毒功能区以及功能区是否具有独立的抗病毒活性仍不清楚。本研究拟鉴定MxA蛋白上的抗乙肝病毒活性肽。首先从全长MxA构建缺失突变体ΔCID和截短体CID,以HepG2.2.15细胞为病毒模型,分别转染空载质粒、MxA、ΔCID和CID,免疫荧光法检测转染效率,Western印迹法检测质粒表达,酶联免疫法测定细胞培养液中HBsAg、HBeAg的量及荧光定量PCR法测定乙肝病毒DNA的量,评估CID段的抗乙肝病毒活性。根据CID段的晶体结构,缩短肽段长度,构建α1、α2、α3等9段肽段质粒,鉴定各段的抗乙肝病毒活性和细胞毒性(MTT法)。运用计算生物学手段——分子对接法预测MxA蛋白与病毒相互作用的模式和位点。结果显示,ΔCID、CID和9段肽段质粒的序列及表达正确,9段肽段的表达量未见显著性差异,无显著的细胞毒性。CID组和黏病毒抗性蛋白A组较对照组乙肝病毒的复制水平显著降低,CID组细胞上清中HBsAg、HBeAg及乙肝病毒DNA的量分别减少了55.57%±8.48%、68.37%±6.24%、66.67%±6.40%,P<0.01;MxA组的3个指标分别减少了61.63%±3.11%、70.77%±7.25%、73.73%±6.18%,P<0.01;ΔCID组较对照组无明显变化。9段肽段中α1组较对照组HBsAg、HBeAg及乙肝病毒DNA的量有显著下降,分别减少了48.33%±1.70%、70.67%±3.30%、68.95%±2.55%,P<0.001,表明α1对乙肝病毒具有强抑制活性。分子对接的结果显示,384~408位氨基酸是MxA蛋白与病毒互作的关键位点,该区域落在α1肽段上,验证了α1是MxA蛋白抗乙肝病毒及与乙肝病毒相互作用中的关键区段。本研究筛选并鉴定出人干扰素诱导蛋白MxA上最有效的抗乙肝病毒活性肽α1,研究结果为抗乙肝病毒多肽类新药的研发奠定了基础。
基金supported by the National Science Foundation of China(81271818 and 81471940 to YF,and 81471941,81871659 and 81828005 to WH)
文摘The human myxovirus resistance 2(Mx2/Mx B)protein,a member of interferon(IFN)-inducible dynamin-like large GTPases,restricts a number of virus infections.Inhibition of these viruses occurs at poorly-defined steps after viral entry and has a common requirement for Mx B oligomerization.However,the GTPase activity is essential for the anti-viral effects of Mx B against herpesviruses and HBV but not HIV-1.To understand the role of Mx B GTPase activity,including GTP binding and GTP hydrolysis,in restriction of HIV-1 infection,we genetically separated these two functions and evaluated their contributions to restriction.We found that both the GTP binding and hydrolysis function of Mx B involved in the restriction of HIV-1 replication.The GTPase activity of Mx B contributed to its nuclear location,interaction with nucleoporins(NUPs)and HIV-1 capsids.Furthermore,Mx B disrupted the association between NUPs and HIV-1 cores dependently upon its GTPase activity.The function of GTPase activity was therefore multi-faceted,led to fundamentally distinct mechanisms employed by wild-type Mx B and GTPase activity defective Mx B mutations to restrict HIV-1 replication.
