Herpes simplex virus 1 (HSV-1) UL20 plays a crucial role in the envelopment of the cytoplasmic virion and its egress. It is a nonglycosylated envelope protein that is regulated as a γ1 gene. Two-hybrid and pulldown assays demonstrated that UL20, but no other HSV-1 gene-encoded proteins, binds specifically to GODZ (also known as DHHC3), a cellular Golgi apparatus-specific Asp-His-His-Cys (DHHC) zinc finger protein. A catalytically inactive dominant-negative GODZ construct significantly reduced HSV-1 replication in vitro and affected the localization of UL20 and glycoprotein K (gK) and their interactions but not glycoprotein C (gC). GODZ is involved in palmitoylation, and we found that UL20 is palmitoylated by GODZ using a GODZ dominant-negative plasmid. Blocking of palmitoylation using 2-bromopalmitate (2-BP) affected the virus titer and the interaction of UL20 and gK but did not affect the levels of these proteins. In conclusion, we have shown that binding of UL20 to GODZ in the Golgi apparatus regulates trafficking of UL20 and its subsequent effects on gK localization and virus replication. We also have demonstrated that GODZ-mediated UL20 palmitoylation is critical for UL20 membrane targeting and thus gK cell surface expression, providing new mechanistic insights into how UL20 palmitoylation regulates HSV-1 infectivity.

IMPORTANCE HSV-1 UL20 is a nonglycosylated essential envelope protein that is highly conserved among herpesviruses. In this study, we show that (i) HSV-1 UL20 binds to GODZ (also known as DHHC3), a Golgi apparatus-specific Asp-His-His-Cys (DHHC) zinc finger protein; (ii) a GODZ dominant-negative mutant and an inhibitor of palmitoylation reduced HSV-1 titers and altered the localization of UL20 and glycoprotein K; and (iii) UL20 is palmitoylated by GODZ, and this UL20 palmitoylation is required for HSV-1 infectivity. Thus, blocking of the interaction of UL20 with GODZ, using a GODZ dominant-negative mutant or possibly GODZ shRNA, should be considered a potential alternative therapy in not only HSV-1 but also other conditions in which GODZ processing is an integral component of pathogenesis.

单纯疱疹病毒1（HSV-1）UL20在包封胞质病毒粒子及其外出过程中起着至关重要的作用。它是一种非糖基化的包膜蛋白，被调节为γ1基因。两种杂交和下拉实验表明，UL20，但没有其他HSV-1基因编码的蛋白，与GODZ（也称为DHHC3）特异性结合，GODZ是细胞高尔基体特有的Asp-His-His-Cys（DHHC）锌指蛋白质。催化失活的显性负性GODZ构建体在体外显着降低了HSV-1复制并影响UL20和糖蛋白K（gK）的定位及其相互作用，但不影响糖蛋白C（gC）。GODZ参与棕榈酰化，并且我们发现使用GODZ显性阴性质粒，UL20被GODZ棕榈酰化。使用2-溴棕榈酸酯（2-BP）阻止棕榈酰化会影响病毒滴度以及UL20和gK的相互作用，但不会影响这些蛋白质的水平。总之，我们已经表明，高尔基体中UL20与GODZ的结合可调节UL20的运输及其对gK定位和病毒复制的后续影响。我们还证明了GODZ介导的UL20棕榈酰化对于UL20膜靶向以及gK细胞表面表达至关重要，从而提供了有关UL20棕榈酰化如何调节HSV-1感染性的新机制。

重要事项HSV-1 UL20是非糖基化的必需包膜蛋白，在疱疹病毒中高度保守。在这项研究中，我们显示（i）HSV-1 UL20与GODZ（也称为DHHC3）结合，这是一种高尔基体特异性的Asp-His-His-Cys（DHHC）锌指蛋白；（ii）GODZ显性阴性突变体和棕榈酰化抑制剂可降低HSV-1滴度并改变UL20和糖蛋白K的定位；（iii）UL20被GODZ棕榈酰化，而这种UL20棕榈酰化是HSV-1感染性所必需的。因此，使用GODZ显性阴性突变体或可能使用GODZ shRNA阻断UL20与GODZ的相互作用，不仅应被认为是HSV-1的潜在替代疗法，而且还应考虑其他条件，其中GODZ加工是发病机理的组成部分。