EBNA1-mediated recruitment of a histone H2B deubiquitylating complex to the Epstein-Barr virus latent origin of DNA replication.
EBNA1-mediated recruitment of a histone H2B deubiquitylating complex to the Epstein-Barr virus latent origin of DNA replication.
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DOI：
10.1371/journal.ppat.1000624
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发表时间：
2009-10
期刊：
影响因子：
6.7
通讯作者：
Frappier L
中科院分区：
文献类型：
--
作者：
Sarkari F;Sanchez-Alcaraz T;Wang S;Holowaty MN;Sheng Y;Frappier L
EB病毒（EBV）的EBNA 1蛋白在使潜伏感染细胞中的EBV基因组能够复制和持续存在以及激活EBV潜伏基因表达中起重要作用，在所有情况下通过结合至潜伏复制起点oriP中的特异性识别位点。在这里，我们表明，EBNA 1结合到其识别位点在体外大大刺激结合到细胞去泛素化酶，USP 7，和USP 7可以形成一个三元复合物与DNA结合EBNA 1。与体外效应一致，USP 7沉默降低了人细胞中oriP元件上EBNA 1的组装，而USP 7结合缺陷的EBNA 1突变体的组装不受影响。USP 7亲和柱分析鉴定了USP 7和人GMP合成酶（GMPS）之间的复合物，该复合物显示出刺激USP 7在体外从组蛋白H2 B切割单泛素的能力。因此，人细胞中USP 7的沉默导致单乙酰基化H2 B水平的一致增加。USP 7-GMPS复合物在体外与DNA结合的EBNA 1形成四元复合物，并且在EBV感染的细胞中，优先在oriP功能元件FR处与EBNA 1一起沿着检测到。USP 7的下调降低了FR处的GMPS水平，增加了起源的该区域中的monoubiquitylated H2 B的水平，并且降低了EBNA 1（但不是EBNA 1 USP 7结合突变体）激活FR转录的能力。结果表明，USP 7可以刺激EBNA 1-DNA相互作用，并且EBNA 1可以通过招募USP 7来改变oriP处的组蛋白修饰。EB病毒（EBV）感染在宿主的一生中持续存在，这主要是由于EBNA 1病毒蛋白的作用。EBNA 1使EBV基因组能够复制和稳定持续存在，并通过结合EBV基因组中的特定DNA序列来激活其他EBV基因的表达。我们已经表明，细胞蛋白USP 7刺激EBNA 1结合其DNA序列，EBNA 1招募USP 7到EBV基因组，这反过来又招募另一种细胞蛋白GMP合成酶。USP 7和GMP合成酶的复合物然后起作用以改变控制EBV持久性的EBV基因组区域的染色质结构。EBV基因组的这些变化对于使EBV基因组在感染细胞中持续存在可能是重要的。
The EBNA1 protein of Epstein-Barr virus (EBV) plays essential roles in enabling the replication and persistence of EBV genomes in latently infected cells and activating EBV latent gene expression, in all cases by binding to specific recognition sites in the latent origin of replication, oriP. Here we show that EBNA1 binding to its recognition sites in vitro is greatly stimulated by binding to the cellular deubiquitylating enzyme, USP7, and that USP7 can form a ternary complex with DNA-bound EBNA1. Consistent with the in vitro effects, the assembly of EBNA1 on oriP elements in human cells was decreased by USP7 silencing, whereas assembly of an EBNA1 mutant defective in USP7 binding was unaffected. USP7 affinity column profiling identified a complex between USP7 and human GMP synthetase (GMPS), which was shown to stimulate the ability of USP7 to cleave monoubiquitin from histone H2B in vitro. Accordingly, silencing of USP7 in human cells resulted in a consistent increase in the level of monoubquitylated H2B. The USP7-GMPS complex formed a quaternary complex with DNA-bound EBNA1 in vitro and, in EBV infected cells, was preferentially detected at the oriP functional element, FR, along with EBNA1. Down-regulation of USP7 reduced the level of GMPS at the FR, increased the level of monoubiquitylated H2B in this region of the origin and decreased the ability of EBNA1, but not an EBNA1 USP7-binding mutant, to activate transcription from the FR. The results indicate that USP7 can stimulate EBNA1-DNA interactions and that EBNA1 can alter histone modification at oriP through recruitment of USP7. Epstein-Barr virus (EBV) infections persist for the lifetime of the host largely due to the actions of the EBNA1 viral protein. EBNA1 enables the replication and stable persistence of EBV genomes and activates the expression of other EBV genes by binding to specific DNA sequences in the EBV genome. We have shown that the cellular protein USP7 stimulates EBNA1 binding to its DNA sequences and that EBNA1 recruits USP7 to the EBV genome, which in turn recruits another cellular protein GMP synthetase. The complex of USP7 and GMP synthetase then functions to alter the chromatin structure at a region of the EBV genome that controls EBV persistence. These changes to the EBV genome are likely important for enabling the persistence of EBV genomes in infected cells.
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影响因子：
64.5
作者：
Bochkarev, A;Barwell, JA;Edwards, AM
通讯作者：
Edwards, AM
影响因子：
11.4
作者：
HSIEH, DJ;CAMIOLO, SM;YATES, JL
通讯作者：
YATES, JL
影响因子：
5.4
作者：
CHEN, MR;MIDDELDORP, JM;HAYWARD, SD
通讯作者：
HAYWARD, SD
影响因子：
5.4
作者：
Ceccarelli, DFJ;Frappier, L
通讯作者：
Frappier, L
DOI：
10.1073/pnas.88.23.10875
发表时间：
1991-12-01
影响因子：
11.1
作者：
FRAPPIER, L;ODONNELL, M
通讯作者：
ODONNELL, M