Viral mimicry of Cdc2/cyclin-dependent kinase 1 mediates disruption of nuclear lamina during human cytomegalovirus nuclear egress.
Viral mimicry of Cdc2/cyclin-dependent kinase 1 mediates disruption of nuclear lamina during human cytomegalovirus nuclear egress.
复制标题
DOI：
10.1371/journal.ppat.1000275
复制
发表时间：
2009-01
期刊：
影响因子：
6.7
通讯作者：
Coen DM
中科院分区：
文献类型：
--
作者：
Hamirally S;Kamil JP;Ndassa-Colday YM;Lin AJ;Jahng WJ;Baek MC;Noton S;Silva LA;Simpson-Holley M;Knipe DM;Golan DE;Marto JA;Coen DM
核层是疱疹病毒核衣壳从细胞核进入细胞质（核出口）时遇到的主要障碍。我们发现人类巨细胞病毒（HCMV）编码的蛋白激酶UL97是有效的核出口所必需的，在体外，Cdc2/细胞周期蛋白依赖性激酶1（在有丝分裂过程中负责分解核层）靶向的位点上磷酸化核层成分层蛋白A/C。定量质谱分析比较了从表达UL97活性或缺乏UL97活性的病毒感染的细胞中分离的纤层蛋白A/C，发现纤层蛋白A/C在残基22 （Ser22）的丝氨酸上发生UL97依赖性磷酸化。用UL97激酶活性抑制剂马里巴韦（maribavir）短暂处理HCMV感染的细胞，可使纤层蛋白A/C磷酸化减少约50%，这与UL97在HCMV复制过程中直接磷酸化纤层蛋白A/C一致。在病毒复制过程中，核层蛋白A/C的磷酸化伴随着细胞核形状的改变，以及核层变薄、内陷和离散断裂，所有这些都需要UL97的活性。由于Ser22是一个磷酸化位点，与层状蛋白a /C分解特别密切相关，我们的数据支持一个模型，其中病毒模仿有丝分裂宿主细胞激酶活性促进核出口，同时适应病毒对细胞周期的阻滞。人类巨细胞病毒（HCMV）在移植患者和艾滋病患者中引起危及生命的疾病，也是导致出生缺陷的重要原因。像所有的病毒一样，HCMV必须有一种离开宿主细胞的方式，这样它才能感染新的细胞。此外，作为疱疹病毒家族的一员，HCMV在细胞核中复制其DNA，因此它必须具有确保其遗传物质可以从细胞核中退出的机制（核出口）。HCMV编码一种蛋白激酶UL97，这是核有效输出所必需的。我们发现UL97通过模拟宿主细胞酶来帮助细胞核出口，而宿主细胞酶通常在细胞分裂过程中帮助分解细胞核中的蛋白质网。UL97的酶活性在网状结构上戳洞，使新生的HCMV病毒粒子能够进入核膜。UL97也是治疗HCMV疾病药物的重要靶点。这项工作不仅有助于解释这些药物是如何起作用的，而且还强调了针对核出口发现新药的潜力。
The nuclear lamina is a major obstacle encountered by herpesvirus nucleocapsids in their passage from the nucleus to the cytoplasm (nuclear egress). We found that the human cytomegalovirus (HCMV)-encoded protein kinase UL97, which is required for efficient nuclear egress, phosphorylates the nuclear lamina component lamin A/C in vitro on sites targeted by Cdc2/cyclin-dependent kinase 1, the enzyme that is responsible for breaking down the nuclear lamina during mitosis. Quantitative mass spectrometry analyses, comparing lamin A/C isolated from cells infected with viruses either expressing or lacking UL97 activity, revealed UL97-dependent phosphorylation of lamin A/C on the serine at residue 22 (Ser22). Transient treatment of HCMV-infected cells with maribavir, an inhibitor of UL97 kinase activity, reduced lamin A/C phosphorylation by approximately 50%, consistent with UL97 directly phosphorylating lamin A/C during HCMV replication. Phosphorylation of lamin A/C during viral replication was accompanied by changes in the shape of the nucleus, as well as thinning, invaginations, and discrete breaks in the nuclear lamina, all of which required UL97 activity. As Ser22 is a phosphorylation site of particularly strong relevance for lamin A/C disassembly, our data support a model wherein viral mimicry of a mitotic host cell kinase activity promotes nuclear egress while accommodating viral arrest of the cell cycle. Human cytomegalovirus (HCMV) causes life-threatening disease in transplant patients and people with AIDS, and is also an important cause of birth defects. Like all viruses, HCMV must have a way to leave the host cell, so that it can infect new cells. Moreover, as a member of the herpesvirus family, HCMV replicates its DNA in the nucleus, so it must have mechanisms to ensure that its genetic material can exit from the nucleus (nuclear egress). HCMV encodes a protein kinase, UL97, which is required for efficient nuclear egress. We found that UL97 aids nuclear egress by mimicking a host cell enzyme that normally helps break down a protein meshwork in the nucleus during cell division. The enzyme activity of UL97 pokes holes in the meshwork that allow nascent HCMV virions to gain access to the nuclear membrane. UL97 is also an important target for drugs for treating HCMV disease. This work not only helps explain how these drugs act, but also highlights the potential of targeting nuclear egress for the discovery of new drugs.
登录
查看更多内容
影响因子：
6.7
作者：
Hertel L;Chou S;Mocarski ES
通讯作者：
Mocarski ES
影响因子：
5.4
作者：
Bubeck, A;Wagner, M;Koszinowski, UH
通讯作者：
Koszinowski, UH
DOI：
10.1111/j.1432-1033.1993.tb17806.x
发表时间：
1993-04-15
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
EGGERT, M;RADOMSKI, N;JOST, E
通讯作者：
JOST, E
影响因子：
5.4
作者：
Kamil, JP;Tischer, BK;Kung, HJ
通讯作者：
Kung, HJ
影响因子：
3.7
作者：
Bresnahan, WA;Boldogh, I;Albrecht, T
通讯作者：
Albrecht, T