Differential Phosphatidylinositol-3-Kinase-Akt-mTOR Activation by Semliki Forest and Chikungunya Viruses Is Dependent on nsP3 and Connected to Replication Complex Internalization
Differential Phosphatidylinositol-3-Kinase-Akt-mTOR Activation by Semliki Forest and Chikungunya Viruses Is Dependent on nsP3 and Connected to Replication Complex Internalization
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Semliki 森林和基孔肯雅病毒对磷脂酰肌醇-3-激酶-Akt-mTOR 的差异激活依赖于 nsP3 并与复制复合体内化有关
DOI：
10.1128/jvi.01579-15
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发表时间：
2015
影响因子：
5.4
通讯作者：
McInerney GM
中科院分区：
文献类型：
--
作者：
Thaa B;Biasiotto R;Neuvonen M;Götte B;Rheinemann L;Mutso M;Varghese F;Balistreri G;Merits A;Ahola T;McInerney GM
许多病毒影响或利用磷脂酰肌醇-3-激酶（PI 3 K）-Akt-哺乳动物雷帕霉素靶蛋白（mTOR）通路，这是一种重要的促生存信号级联。我们报告说，这种途径被强烈激活后，感染旧世界甲病毒塞姆利基森林病毒（SFV）的细胞，即使在完全营养饥饿的条件下。我们将这种激活映射到SFV非结构蛋白nsP 3 C-末端尾部的过度磷酸化/酸性结构域。在nsP 3中缺失该结构域（SFV-Δ50）但不缺失其他区域的病毒显示出明显延迟和降低的Akt刺激能力。SFV野生型的nsP 3（nsP 3-wt）而非nsP 3-Δ50的异位表达（配备有膜锚）足以激活Akt。我们将PI 3 K-Akt-mTOR刺激与病毒复制复合物的细胞内动力学联系起来，病毒复制复合物在质膜上形成，随后在PI 3 K抑制剂渥曼青霉素阻断的过程中内化。在用SFV-wt和具有nsP 3缺失的SFV突变体感染细胞后观察到复制复合物内化，但用SFV-Δ50则没有，其中复制复合物通常在细胞外周积累。在感染了密切相关的基孔肯雅病毒（CHIKV）的细胞中，PI 3 K-Akt-mTOR通路仅被中度激活。CHIKV的复制复合物主要位于细胞周边。在SFV和CHIKV之间交换nsP 3的高变C末端尾诱导了CHIKV中强PI 3 K-Akt-mTOR活化和复制复合物内化的表型。总之，用SFV而不是CHIKV感染通过nsP 3的过度磷酸化/酸性结构域增强PI 3 K-Akt-mTOR以驱动复制复合物内化。重要的是，SFV和CHIKV在分子和细胞生物学方面非常相似，例如，在复制和分子相互作用方面，CHIKV和SFV是不同的，但在病理学方面却截然不同：CHIKV是一种相关的人类病原体，引起高烧和关节疼痛，而SFV是一种低致病性模型病毒，尽管在小鼠中具有神经致病性。我们发现SFV和CHIKV都激活细胞中的促存活PI 3 K-Akt-mTOR通路，但它们这样做的能力有很大差异：Akt被SFV感染强烈和持续激活，但仅被CHIKV中度激活。我们将这种激活能力映射到SFV的非结构蛋白3（nsP 3）中的一个区域，并可以将该区域功能性地转移到CHIKV。Akt激活与复制复合物的亚细胞动力学有关，SFV（但不是CHIKV）可以从细胞外周有效内化复制复合物。这种信号通路刺激和复制复合物定位的差异可能对病理学有影响。
Many viruses affect or exploit the phosphatidylinositol-3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway, a crucial prosurvival signaling cascade. We report that this pathway was strongly activated in cells upon infection with the Old World alphavirus Semliki Forest virus (SFV), even under conditions of complete nutrient starvation. We mapped this activation to the hyperphosphorylated/acidic domain in the C-terminal tail of SFV nonstructural protein nsP3. Viruses with a deletion of this domain (SFV-Δ50) but not of other regions in nsP3 displayed a clearly delayed and reduced capacity of Akt stimulation. Ectopic expression of the nsP3 of SFV wild type (nsP3-wt), but not nsP3-Δ50, equipped with a membrane anchor was sufficient to activate Akt. We linked PI3K-Akt-mTOR stimulation to the intracellular dynamics of viral replication complexes, which are formed at the plasma membrane and subsequently internalized in a process blocked by the PI3K inhibitor wortmannin. Replication complex internalization was observed upon infection of cells with SFV-wt and SFV mutants with deletions in nsP3 but not with SFV-Δ50, where replication complexes were typically accumulated at the cell periphery. In cells infected with the closely related chikungunya virus (CHIKV), the PI3K-Akt-mTOR pathway was only moderately activated. Replication complexes of CHIKV were predominantly located at the cell periphery. Exchanging the hypervariable C-terminal tail of nsP3 between SFV and CHIKV induced the phenotype of strong PI3K-Akt-mTOR activation and replication complex internalization in CHIKV. In conclusion, infection with SFV but not CHIKV boosts PI3K-Akt-mTOR through the hyperphosphorylated/acidic domain of nsP3 to drive replication complex internalization.IMPORTANCESFV and CHIKV are very similar in terms of molecular and cell biology, e.g., regarding replication and molecular interactions, but are strikingly different regarding pathology: CHIKV is a relevant human pathogen, causing high fever and joint pain, while SFV is a low-pathogenic model virus, albeit neuropathogenic in mice. We show that both SFV and CHIKV activate the prosurvival PI3K-Akt-mTOR pathway in cells but greatly differ in their capacities to do so: Akt is strongly and persistently activated by SFV infection but only moderately activated by CHIKV. We mapped this activation capacity to a region in nonstructural protein 3 (nsP3) of SFV and could functionally transfer this region to CHIKV. Akt activation is linked to the subcellular dynamics of replication complexes, which are efficiently internalized from the cell periphery for SFV but not CHIKV. This difference in signal pathway stimulation and replication complex localization may have implications for pathology.
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通过噬菌斑减少中和测试确定 A 组虫媒病毒的抗原关系。
DOI：
10.4269/ajtmh.1975.24.527
发表时间：
1975
期刊：
The American journal of tropical medicine and hygiene
影响因子：
--
作者：
N. Karabatsos
通讯作者：
N. Karabatsos
影响因子：
5.4
作者：
Salonen, A;Vasiljeva, L;Kääriäinen, L
通讯作者：
Kääriäinen, L
影响因子：
3.1
作者：
McInerney, Gerald M.
通讯作者：
McInerney, Gerald M.
影响因子：
5.4
作者：
Scholte, Florine E. M.;Tas, Ali;van Hemert, Martijn J.
通讯作者：
van Hemert, Martijn J.
Semliki森林病毒非结构蛋白3的磷酸化位点分析。
影响因子：
4.8
作者：
H. Vihinen;J. Saarinen
通讯作者：
J. Saarinen