Inactivation of Uaf1 Causes Defective Homologous Recombination and Early Embryonic Lethality in Mice
Inactivation of Uaf1 Causes Defective Homologous Recombination and Early Embryonic Lethality in Mice
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DOI：
10.1128/mcb.00870-13
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发表时间：
2013-11-01
影响因子：
5.3
通讯作者：
D'Andrea, Alan D.
中科院分区：
文献类型：
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作者：
Park, Eunmi;Kim, Jung Min;D'Andrea, Alan D.
去泛素化酶异二聚体复合物USP1-UAF1调节范可尼贫血（FA） DNA修复途径。这种复合物的缺失导致泛素化FANCD2 （FANCD2- ub）和泛素化PCNA （PCNA- ub）的细胞水平升高。缺乏该复合物催化亚基USP1的小鼠表现出fa样表型，并且同源重组（HR）修复的细胞缺陷。在这里，我们描述了UAF1亚基缺失的小鼠。Uaf1（+/-）小鼠出生时体积小，生育能力降低，与Usp1（-/-）小鼠相似。出乎意料的是，纯合子Uaf1（-/-）胚胎在胚胎第7.5天死亡（E7.5）。这些突变胚胎很小，发育迟缓。正如预期的那样，小鼠Uaf1缺乏导致细胞中Fancd2-Ub和Pcna-Ub水平升高。Uaf1（+/-）小鼠胚胎成纤维细胞（MEFs）表现出严重的染色体不稳定性、基因毒素过敏和同源重组修复的显著缺陷。此外，Uaf1（-/-）小鼠胚胎干细胞（mESCs）表现出染色体不稳定、基因毒素过敏和Fancd2焦点组装受损。与USP1敲低相似，UAF1在肿瘤细胞中的敲低在体内引起肿瘤生长的抑制。综上所述，我们的数据证明了USP1-UAF1复合体通过调节FANCD2-Ub和PCNA-Ub细胞池在HR修复中的重要调节作用。
The deubiquitinating enzyme heterodimeric complex USP1-UAF1 regulates the Fanconi anemia (FA) DNA repair pathway. Absence of this complex leads to increased cellular levels of ubiquitinated FANCD2 (FANCD2-Ub) and ubiquitinated PCNA (PCNA-Ub). Mice deficient in the catalytic subunit of the complex, USP1, exhibit an FA-like phenotype and have a cellular deficiency in homologous-recombination (HR) repair. Here, we have characterized mice deficient in the UAF1 subunit. Uaf1(+/-) mice were small at birth and exhibited reduced fertility, thus resembling Usp1(-/-) mice. Unexpectedly, homozygous Uaf1(-/-) embryos died at embryonic day 7.5 (E7.5). These mutant embryos were small and developmentally retarded. As expected, Uaf1 deficiency in mice led to increased levels of cellular Fancd2-Ub and Pcna-Ub. Uaf1(+/-) murine embryonic fibroblasts (MEFs) exhibited profound chromosome instability, genotoxin hypersensitivity, and a significant defect in homologous-recombination repair. Moreover, Uaf1(-/-) mouse embryonic stem cells (mESCs) showed chromosome instability, genotoxin hypersensitivity, and impaired Fancd2 focus assembly. Similar to USP1 knockdown, UAF1 knockdown in tumor cells caused suppression of tumor growth in vivo. Taken together, our data demonstrate the important regulatory role of the USP1-UAF1 complex in HR repair through its regulation of the FANCD2-Ub and PCNA-Ub cellular pools.