Urano Emiko, Aoki Toru, Futahashi Yuko, Murakami Tsutomu, Morikawa Yuko, Yamamoto Naoki, Komano Jun
Kitasato Institute of Life Sciences, Kitasato University, Shirokane 5-9-1, Minato-ku, Tokyo 108-8641, Japan.
AIDS Research Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
J Gen Virol. 2008 Dec;89(Pt 12):3144-3149. doi: 10.1099/vir.0.2008/004820-0.
The matrix domain (MA) of human immunodeficiency virus type 1 Pr55Gag is covalently modified with a myristoyl group that mediates efficient viral production. However, the role of myristoylation, particularly in the viral entry process, remains uninvestigated. This study replaced the myristoylation signal of MA with a well-studied phosphatidylinositol 4,5-biphosphate-binding plasma membrane (PM) targeting motif, the phospholipase C-delta1 pleckstrin homology (PH) domain. PH-Gag-Pol PM targeting and viral production efficiencies were improved compared with Gag-Pol, consistent with the estimated increases in Gag-PM affinity. Both virions were recovered in similar sucrose density-gradient fractions and had similar mature virion morphologies. Importantly, PH-Gag-Pol and Gag-Pol pseudovirions had almost identical infectivity, suggesting a dispensable role for myristoylation in the virus life cycle. PH-Gag-Pol might be useful in separating the myristoylation-dependent processes from the myristoylation-independent processes. This the first report demonstrating infectious pseudovirion production without myristoylated Pr55Gag.
人类免疫缺陷病毒1型Pr55Gag的基质结构域（MA）通过肉豆蔻酰基进行共价修饰，该修饰介导高效的病毒产生。然而，肉豆蔻酰化的作用，尤其是在病毒进入过程中的作用，仍未得到研究。本研究用一个研究充分的磷脂酰肌醇4,5-二磷酸结合质膜（PM）靶向基序——磷脂酶C-δ1普列克底物蛋白同源（PH）结构域，取代了MA的肉豆蔻酰化信号。与Gag-Pol相比，PH-Gag-Pol的PM靶向和病毒产生效率有所提高，这与Gag与PM亲和力的估计增加一致。两种病毒粒子在相似的蔗糖密度梯度级分中回收，并且具有相似的成熟病毒粒子形态。重要的是，PH-Gag-Pol和Gag-Pol假病毒具有几乎相同的感染性，这表明肉豆蔻酰化在病毒生命周期中作用不大。PH-Gag-Pol可能有助于区分依赖肉豆蔻酰化的过程和不依赖肉豆蔻酰化的过程。这是第一份证明在没有肉豆蔻酰化的Pr55Gag情况下产生感染性假病毒的报告。
