The deubiquitylase USP15 regulates topoisomerase II alpha to maintain genome integrity.
The deubiquitylase USP15 regulates topoisomerase II alpha to maintain genome integrity.
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DOI：
10.1038/s41388-017-0092-0
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发表时间：
2018-04
期刊：
影响因子：
8
通讯作者：
Coulson JM
中科院分区：
文献类型：
--
作者：
Fielding AB;Concannon M;Darling S;Rusilowicz-Jones EV;Sacco JJ;Prior IA;Clague MJ;Urbé S;Coulson JM
泛素特异性蛋白酶15 （USP15）是一种广泛表达的去泛素化酶，在癌症的多种细胞过程中都有涉及。在这里，我们发现拓扑异构酶II （TOP2A）是一种由USP15调节的新蛋白。TOP2A在G2期间积累，并在前期对缠绕在一起的姐妹染色单体进行decatenate，确保复制的基因组能够在后期准确地分裂成子细胞。我们发现，TOP2A的积累需要USP15，而USP15的缺失导致后期染色体桥的形成。这些桥不能衰减，在有丝分裂结束时形成微核，这表明基因组不稳定。我们还描述了USP15的两个主要异构体的细胞周期依赖行为，它们的不同之处在于一个短的富含丝氨酸的插入，该插入保留在异构体1中，而不保留在异构体2中。虽然USP15在间期主要存在于细胞质中，但我们发现这两种异构体都在前期进入细胞核，但在有丝分裂进入时，异构体1在其独特的S229残基上被磷酸化。我们观察到的USP15耗损的微核表型可以通过USP15异构体拯救，并且需要USP15的催化活性。然而，重要的是，USP15 - isoform-1的S229D磷酸化模拟突变体既不能挽救微核表型，也不能挽救TOP2A的积累。因此，S229磷酸化选择性地取消了USP15在维持基因组完整性方面的作用。最后，我们发现USP15亚型-1在一组非小细胞肺癌细胞系中优先上调，并提出亚型失衡可能导致癌症基因组不稳定。我们的数据提供了第一个异构特异性去泛素化酶磷酸化调控的例子，并揭示了USP15在保护基因组完整性方面的新作用。
Ubiquitin-specific protease 15 (USP15) is a widely expressed deubiquitylase that has been implicated in diverse cellular processes in cancer. Here we identify topoisomerase II (TOP2A) as a novel protein that is regulated by USP15. TOP2A accumulates during G2 and functions to decatenate intertwined sister chromatids at prophase, ensuring the replicated genome can be accurately divided into daughter cells at anaphase. We show that USP15 is required for TOP2A accumulation, and that USP15 depletion leads to the formation of anaphase chromosome bridges. These bridges fail to decatenate, and at mitotic exit form micronuclei that are indicative of genome instability. We also describe the cell cycle-dependent behaviour for two major isoforms of USP15, which differ by a short serine-rich insertion that is retained in isoform-1 but not in isoform-2. Although USP15 is predominantly cytoplasmic in interphase, we show that both isoforms move into the nucleus at prophase, but that isoform-1 is phosphorylated on its unique S229 residue at mitotic entry. The micronuclei phenotype we observe on USP15 depletion can be rescued by either USP15 isoform and requires USP15 catalytic activity. Importantly, however, an S229D phospho-mimetic mutant of USP15 isoform-1 cannot rescue either the micronuclei phenotype, or accumulation of TOP2A. Thus, S229 phosphorylation selectively abrogates this role of USP15 in maintaining genome integrity in an isoform-specific manner. Finally, we show that USP15 isoform-1 is preferentially upregulated in a panel of non-small cell lung cancer cell lines, and propose that isoform imbalance may contribute to genome instability in cancer. Our data provide the first example of isoform-specific deubiquitylase phospho-regulation and reveal a novel role for USP15 in guarding genome integrity.
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影响因子：
9.2
作者：
Hagting, A;Jackman, M;Pines, J
通讯作者：
Pines, J
影响因子：
14.9
作者：
Gauthier NP;Larsen ME;Wernersson R;de Lichtenberg U;Jensen LJ;Brunak S;Jensen TS
通讯作者：
Jensen TS
影响因子：
7.3
作者：
Gao J;Aksoy BA;Dogrusoz U;Dresdner G;Gross B;Sumer SO;Sun Y;Jacobsen A;Sinha R;Larsson E;Cerami E;Sander C;Schultz N
通讯作者：
Schultz N
影响因子：
8
作者：
Bower, J. J.;Karaca, G. F.;Zhou, Y.;Simpson, D. A.;Cordeiro-Stone, M.;Kaufmann, W. K.
通讯作者：
Kaufmann, W. K.
DOI：
10.1073/pnas.88.20.8895
发表时间：
1991-10-01
影响因子：
11.1
作者：
DOWNES, CS;MULLINGER, AM;JOHNSON, RT
通讯作者：
JOHNSON, RT