Substitution of Herpes Simplex Virus 1 Entry Glycoproteins with Those of Saimiriine Herpesvirus 1 Reveals a gD-gH/gL Functional Interaction and a Region within the gD Profusion Domain That Is Critical for Fusion
Substitution of Herpes Simplex Virus 1 Entry Glycoproteins with Those of Saimiriine Herpesvirus 1 Reveals a gD-gH/gL Functional Interaction and a Region within the gD Profusion Domain That Is Critical for Fusion
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DOI：
10.1128/jvi.00465-14
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发表时间：
2014-06-01
影响因子：
5.4
通讯作者：
Connolly, Sarah A.
中科院分区：
文献类型：
--
作者：
Fan, Qing;Longnecker, Richard;Connolly, Sarah A.
为了深入了解疱疹病毒进入细胞的机制，从甲型疱疹病毒家族灵长类成员赛米林疱疹病毒1型(SaHV-1)基因组中克隆了单纯疱疹病毒(HSV)融合所需的4种糖蛋白。细胞-细胞融合分析表明，SaHV-1进入糖蛋白与先前已知的甲型疱疹病毒进入受体Nectin-1和CD155一起发挥作用，但不与疱疹病毒进入介质(HVEM)或成对的免疫球蛋白样2型受体α(PILRα)起作用。用SAHV-1 gD同源物替换HSV-1 gD，与HSV-1 gB和Gh/g1共表达时，融合功能完全丧失。HSV-1 gD与SaHV-1 gB和Gh/g1共表达时，HSV-1 gD也不能替代SaHV-1 gD。同样，HSV-1和SaHV-1的Gh/Gl异源二聚体不能互换。相反，HSV-1和SaHV-1 GB同源物在异型背景下都保留了功能。这些结果表明，在HSV-1和SaHV-1进入过程中，同型gD和Gh/g1之间发生了重要的相互作用。为了绘制这种同型相互作用的位置，我们创建了一系列GD嵌合体，重点放在由HSV-1 gD残基261至305或SaHV-1 gD残基264至307组成的“丰富结构域”(PFD)上。我们在SaHV-1 gD PFD的N端发现了一个7个氨基酸的延伸片段(264个RTLPPK 270)，这有助于同型融合。最后，我们发现gD受体结合区和pfd不能独立发挥作用，但两者都能抑制野生型gD的功能。
To gain insight into the mechanism of herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the saimiriine herpesvirus 1 (SaHV-1) genome, a primate member of the alphaherpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaherpesvirus entry receptors nectin-1 and CD155 but not with herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILR alpha). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers from HSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interaction between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. To map the site of this homotypic interaction, we created a series of gD chimeras, focusing on the "profusion domain" (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD.