The antiviral protein, viperin, localizes to lipid droplets via its N-terminal amphipathic α-helix
The antiviral protein, viperin, localizes to lipid droplets via its N-terminal amphipathic α-helix
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DOI：
10.1073/pnas.0911679106
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发表时间：
2009-12-01
影响因子：
11.1
通讯作者：
Cresswell, Peter
中科院分区：
文献类型：
--
作者：
Hinson, Ella R.;Cresswell, Peter
脂滴是细胞内储存脂质的细胞器，被认为是来源于内质网（ER）。一些病原体，特别是丙型肝炎病毒，使用脂滴进行复制。关于脂滴是如何产生和被病毒利用的，仍然存在许多问题。在这里，我们表明，干扰素诱导的抗病毒蛋白蝰蛇蛋白，它定位于细胞质面对的ER和抑制HCV，定位于脂滴。我们表明，负责ER定位的蝰蛇蛋白的N-末端两亲性α-螺旋也是必要的，足以将蝰蛇蛋白和荧光蛋白dsRed定位到脂滴。阻止ER结合的α-螺旋中的点突变也破坏脂滴结合，并且连续缺失突变体表明相同数目的螺旋转角对于ER和脂滴结合是必需的。最后，我们表明丙型肝炎病毒蛋白NS 5A的N末端两亲性α螺旋可以将dsRed和蝰蛇蛋白定位于脂滴。这些发现表明，蝰蛇蛋白和NS 5A的两亲性α-螺旋是脂滴靶向结构域，并表明蝰蛇蛋白通过使用与HCV本身所使用的结构域和机制类似的结构域定位于脂滴来抑制HCV。
Lipid droplets are intracellular lipid-storage organelles that are thought to be derived from the endoplasmic reticulum (ER). Several pathogens, notably hepatitis C virus, use lipid droplets for replication. Numerous questions remain about how lipid droplets are generated and used by viruses. Here we show that the IFN-induced antiviral protein viperin, which localizes to the cytosolic face of the ER and inhibits HCV, localizes to lipid droplets. We show that the N-terminal amphipathic alpha-helix of viperin that is responsible for ER localization is also necessary and sufficient to localize both viperin and the fluorescent protein dsRed to lipid droplets. Point mutations in the alpha-helix that prevent ER association also disrupt lipid droplet association, and sequential deletion mutants indicate that the same number of helical turns are necessary for ER and lipid droplet association. Finally, we show that the N-terminal amphipathic alpha-helix of the hepatitis C viral protein NS5A can localize dsRed and viperin to lipid droplets. These findings indicate that the amphipathic alpha-helices of viperin and NS5A are lipid droplet-targeting domains and suggest that viperin inhibits HCV by localizing to lipid droplets using a domain and mechanism similar to that used by HCV itself.