PTIP/Swift is required for efficient PCNA ubiquitination in response to DNA damage
PTIP/Swift is required for efficient PCNA ubiquitination in response to DNA damage
复制标题
DOI：
10.1016/j.dnarep.2008.02.001
复制
发表时间：
2008-05-03
期刊：
影响因子：
3.8
通讯作者：
Blow, J. Julian
中科院分区：
文献类型：
--
作者：
Goehler, Thomas;Munoz, Ivan M.;Blow, J. Julian
增殖细胞核抗原 (PCNA) 的单泛素化可通过专门的 DNA 聚合酶进行跨损伤合成 (TLS)，以复制过去受损的 DNA。我们研究了非洲爪蟾卵提取物和哺乳动物细胞中 TLS 聚合酶的 PCNA 修饰和染色质招募。我们发现，在 UV 或 aphidicolin 诱导的复制应激后，非洲爪蟾 PCNA 变得泛素化和苏酰化。在这些条件下，TLS 聚合酶 eta 被招募到染色质，并且也被单泛素化。 PTIP/Swift 是 ATM/ATR 激酶的接头蛋白。非洲爪蟾提取物中 PTIP/Swift 的免疫耗竭阻止了复制应激过程中有效的 PCNA 泛素化和聚合酶 eta 向染色质的募集。除了 PCNA 泛素化之外，有效聚合酶 eta 募集至染色质也需要 ATR 激酶活性。我们还表明，通过 RNAi 消除哺乳动物细胞中的 PTIP 会减少 DNA 损伤时 PCNA 的泛素化，并且还会减少聚合酶 eta 和重组蛋白 Rad51 向染色质的募集。我们的结果表明 PTIP/Swift 是后生动物避免 DNA 损伤的重要新调节因子。 (c) 2008 Elsevier B.V. 保留所有权利。
Monoubiquitination of proliferating cell nuclear antigen (PCNA) enables translesion synthesis (TLS) by specialized DNA polymerases to replicate past damaged DNA. We have studied PCNA modification and chromatin recruitment of TLS polymerases in Xenopus egg extracts and mammalian cells. We show that Xenopus PCNA becomes ubiquitinated and sumoylated after replication stress induced by UV or aphidicolin. Under these conditions the TLS polymerase eta was recruited to chromatin and also became monoubiquitinated. PTIP/Swift is an adaptor protein for the ATM/ATR kinases. Immunodepletion of PTIP/Swift from Xenopus extracts prevented efficient PCNA ubiquitination and polymerase eta recruitment to chromatin during replicative stress. In addition to PCNA ubiquitination, efficient polymerase eta recruitment to chromatin also required ATR kinase activity. We also show that PTIP depletion from mammalian cells by RNAi reduced PCNA ubiquitination in response to DNA damage, and also decreased the recruitment to chromatin of polymerase eta and the recombination protein Rad51. Our results suggest that PTIP/Swift is an important new regulator of DNA damage avoidance in metazoans. (c) 2008 Elsevier B.V. All rights reserved.