Controlling the subcellular localization of DNA polymerases ι and η via interactions with ubiquitin
Controlling the subcellular localization of DNA polymerases ι and η via interactions with ubiquitin
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DOI：
10.1038/sj.emboj.7601178
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发表时间：
2006-06-21
期刊：
影响因子：
11.4
通讯作者：
Woodgate, Roger
中科院分区：
文献类型：
--
作者：
Plosky, Brian S.;Vidal, Antonio E.;Woodgate, Roger
Y家族DNA聚合酶具有宽敞的活性位点，可以容纳各种各样的几何畸变。因此，它们比高保真复制酶更容易出错。因此，毫不奇怪，这些聚合酶的体内活性受到严格调控，以使它们无意中接近引物末端的可能性最小化。我们在这里报告，这样的机制，人类细胞采用依赖于DNA聚合酶iota和eta与泛素（Ub）之间的特异性和直接的相互作用。事实上，我们表明，这两种聚合酶与自由polyUb链，以及单泛素化增殖细胞核抗原（Ub-PCNA）的非共价相互作用。分离poli（P692 R）和polg（H654 A）的突变体，其在与polyUb和Ub-PCNA的相互作用中有缺陷，同时保留其与未修饰的PCNA相互作用的能力。有趣的是，聚合酶突变体表现出显着较低水平的复制焦点在DNA损伤的反应，从而突出了聚合酶-Ub相互作用在调节TLS聚合酶的访问停滞的复制叉在体内的生物学重要性。
Y-family DNA polymerases have spacious active sites that can accommodate a wide variety of geometric distortions. As a consequence, they are considerably more error-prone than high-fidelity replicases. It is hardly surprising, therefore, that the in vivo activity of these polymerases is tightly regulated, so as to minimize their inadvertent access to primer-termini. We report here that one such mechanism employed by human cells relies on a specific and direct interaction between DNA polymerases iota and eta with ubiquitin ( Ub). Indeed, we show that both polymerases interact noncovalently with free polyUb chains, as well as mono-ubiquitinated proliferating cell nuclear antigen ( Ub-PCNA). Mutants of poli ( P692R) and polg ( H654A) were isolated that are defective in their interactions with polyUb and Ub-PCNA, whilst retaining their ability to interact with unmodified PCNA. Interestingly, the polymerase mutants exhibit significantly lower levels of replication foci in response to DNA damage, thereby highlighting the biological importance of the polymerase-Ub interaction in regulating the access of the TLS polymerases to stalled replication forks in vivo.