PolDIP2 interacts with human PrimPol and enhances its DNA polymerase activities.
PolDIP2 interacts with human PrimPol and enhances its DNA polymerase activities.
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DOI：
10.1093/nar/gkw175
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发表时间：
2016-04-20
影响因子：
14.9
通讯作者：
Doherty AJ
中科院分区：
文献类型：
--
作者：
Guilliam TA;Bailey LJ;Brissett NC;Doherty AJ
翻译合成（TLS）采用专门的DNA聚合酶绕过复制叉停滞病变。PrimPol最近被鉴定为参与DNA损伤耐受的TLS引发酶和聚合酶。在这里，我们确定了一种新型PrimPol结合伴侣PolDIP 2，并描述了它如何调节PrimPol的酶活性。PolDIP 2刺激PrimPol的聚合酶活性，增强其结合DNA的能力和催化结构域的持续合成能力。此外，PolDIP 2刺激PrimPol对8-氧代-7，8-二氢脱氧鸟苷（8-oxoG）病变的效率和无错误旁路。我们表明，PolDIP 2结合PrimPol的催化结构域，并确定潜在的结合位点。最后，我们证明了人类细胞中PolDIP 2的耗尽会导致复制叉率的降低，这与PrimPol−/−细胞中观察到的相似。然而，PrimPol−/−细胞中PolDIP 2的耗尽不会进一步降低复制叉率。总之，这些发现确定PolDIP 2可以调节TLS聚合酶和PrimPol的引物延伸活性，进一步增强了我们对PolDIP 2和PrimPol在真核DNA损伤耐受中的作用的理解。
Translesion synthesis (TLS) employs specialized DNA polymerases to bypass replication fork stalling lesions. PrimPol was recently identified as a TLS primase and polymerase involved in DNA damage tolerance. Here, we identify a novel PrimPol binding partner, PolDIP2, and describe how it regulates PrimPol's enzymatic activities. PolDIP2 stimulates the polymerase activity of PrimPol, enhancing both its capacity to bind DNA and the processivity of the catalytic domain. In addition, PolDIP2 stimulates both the efficiency and error-free bypass of 8-oxo-7,8-dihydrodeoxyguanosine (8-oxoG) lesions by PrimPol. We show that PolDIP2 binds to PrimPol's catalytic domain and identify potential binding sites. Finally, we demonstrate that depletion of PolDIP2 in human cells causes a decrease in replication fork rates, similar to that observed in PrimPol−/− cells. However, depletion of PolDIP2 in PrimPol−/− cells does not produce a further decrease in replication fork rates. Together, these findings establish that PolDIP2 can regulate the TLS polymerase and primer extension activities of PrimPol, further enhancing our understanding of the roles of PolDIP2 and PrimPol in eukaryotic DNA damage tolerance.