The universal suppressor mutation restores membrane budding defects in the HSV-1 nuclear egress complex by stabilizing the oligomeric lattice.
The universal suppressor mutation restores membrane budding defects in the HSV-1 nuclear egress complex by stabilizing the oligomeric lattice.
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DOI：
10.1371/journal.ppat.1011936
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发表时间：
2024-01
期刊：
影响因子：
6.7
通讯作者：
中科院分区：
文献类型：
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细胞核排出是疱疹病毒复制的一个重要过程，新生衣壳从细胞核转移到细胞质。核出口的第一步-在内核膜上出芽-由核出口复合体（NEC）协调。NEC由病毒蛋白UL 31和UL 34组成，当衣壳出芽进入核周空间时，NEC使衣壳周围的膜变形。NEC低聚成一个六边形的膜结合的晶格是必不可少的出芽，因为NEC突变体设计扰动晶格界面降低其出芽能力。以前，我们确定了NEC抑制突变能够恢复萌芽的突变体与削弱六边形晶格。使用一个既定的体外出芽测定和HSV-1感染的细胞实验，我们表明，抑制突变可以恢复出芽到一个广泛的出芽缺陷NEC突变体，从而作为一个通用的抑制。低温电子断层扫描的抑制NEC突变体晶格揭示了一个六角晶格让人想起野生型NEC晶格，而不是替代晶格。使用X射线晶体学的进一步研究表明，抑制突变促进NEC六聚体之间形成新的接触，表面上稳定了六方晶格。这种稳定化策略足够强大，可以克服突变的其他有害影响，这些突变通过不同的机制使NEC晶格不稳定，导致功能性NEC六边形晶格和膜出芽的恢复。疱疹病毒感染大多数人群，建立周期性重新激活的终身感染。成功感染宿主需要在宿主细胞内形成新的病毒颗粒。在病毒装配的早期，衣壳从细胞核移位到细胞质中。这种衣壳核出口的过程由病毒编码的核出口复合物（NEC）介导，当其寡聚成六边形晶格时，该复合物使衣壳周围的膜变形。破坏晶格的突变可以阻断核出口并减少病毒后代的产生，使NEC成为有吸引力的治疗靶点。然而，病毒可以通过抑制突变克服这种突变的抑制作用。在这里，我们表明，一个这样的抑制突变促进新的晶格接触，预计加强晶格。我们假设NEC可以微调其晶格以响应外部扰动，无论是自然的，如膜曲率，还是人为的，如突变。任何靶向NEC晶格形成的治疗方法都必须考虑其内在的灵活性。
Nuclear egress is an essential process in herpesvirus replication whereby nascent capsids translocate from the nucleus to the cytoplasm. This initial step of nuclear egress–budding at the inner nuclear membrane–is coordinated by the nuclear egress complex (NEC). Composed of the viral proteins UL31 and UL34, NEC deforms the membrane around the capsid as the latter buds into the perinuclear space. NEC oligomerization into a hexagonal membrane-bound lattice is essential for budding because NEC mutants designed to perturb lattice interfaces reduce its budding ability. Previously, we identified an NEC suppressor mutation capable of restoring budding to a mutant with a weakened hexagonal lattice. Using an established in-vitro budding assay and HSV-1 infected cell experiments, we show that the suppressor mutation can restore budding to a broad range of budding-deficient NEC mutants thereby acting as a universal suppressor. Cryogenic electron tomography of the suppressor NEC mutant lattice revealed a hexagonal lattice reminiscent of wild-type NEC lattice instead of an alternative lattice. Further investigation using x-ray crystallography showed that the suppressor mutation promoted the formation of new contacts between the NEC hexamers that, ostensibly, stabilized the hexagonal lattice. This stabilization strategy is powerful enough to override the otherwise deleterious effects of mutations that destabilize the NEC lattice by different mechanisms, resulting in a functional NEC hexagonal lattice and restoration of membrane budding. Herpesviruses infect most of the human population, establishing lifelong infections that periodically reactivate. Successful infection of a host requires the formation of new viral particles within host cells. Early in viral assembly, capsids are translocated from the nucleus into the cytoplasm. This process of capsid nuclear egress is mediated by the virally encoded nuclear egress complex (NEC) that deforms the membrane around the capsid as it oligomerizes into a hexagonal lattice. Mutations that disrupt the lattice can block nuclear egress and reduce viral progeny production, making the NEC an attractive therapeutic target. However, the virus can overcome the inhibitory effects of such mutations through suppressor mutations. Here, we show that one such suppressor mutation promotes new lattice contacts that are expected to strengthen the lattice. We hypothesize that the NEC can fine-tune its lattice in response to external perturbations, be they natural such as membrane curvature, or artificial such as mutations. Any therapeutic approach that targets NEC lattice formation must consider its intrinsic flexibility.
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DOI：
10.1016/j.jbc.2022.101625
发表时间：
2022-03
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Schweininger J;Kriegel M;Häge S;Conrad M;Alkhashrom S;Lösing J;Weiler S;Tillmanns J;Egerer-Sieber C;Decker A;Lenac Roviš T;Eichler J;Sticht H;Marschall M;Muller YA
通讯作者：
Muller YA
影响因子：
5.4
作者：
Antinone, Sarah E.;Zaichick, Sofia V.;Smith, Gregory A.
通讯作者：
Smith, Gregory A.
影响因子：
11.4
作者：
Bigalke, Janna M.;Heldwein, Ekaterina E.
通讯作者：
Heldwein, Ekaterina E.
影响因子：
5.4
作者：
Bubeck, A;Wagner, M;Koszinowski, UH
通讯作者：
Koszinowski, UH
影响因子：
7.7
作者：
Draganova, Elizabeth B.;Zhang, Jiayan;Heldwein, Ekaterina E.
通讯作者：
Heldwein, Ekaterina E.