ZIC2-dependent transcriptional regulation is mediated by DNA-dependent protein kinase, poly(ADP-ribose) polymerase, and RNA helicase A
ZIC2-dependent transcriptional regulation is mediated by DNA-dependent protein kinase, poly(ADP-ribose) polymerase, and RNA helicase A
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DOI：
10.1074/jbc.m610821200
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发表时间：
2007-03-30
影响因子：
4.8
通讯作者：
Aruga, Jun
中科院分区：
文献类型：
--
作者：
Ishiguro, Akira;Ideta, Maki;Aruga, Jun
Zic家族的锌指蛋白是动物发育所必需的，如哺乳动物Zic 2突变引起的前脑无裂所证明的。为了确定Zic介导的发育控制的分子机制，我们表征了两种类型的高分子量复合物，包括Zic 2。复合物I由DNA依赖性蛋白激酶催化亚基（DNA-PKcs）、Ku 70/80和聚（ADP-核糖）聚合酶组成;复合物II由Ku 70/80和RNA解旋酶A组成;所有组分均与Zic 2蛋白直接相互作用。免疫沉淀、亚胶束定位和体外磷酸化分析表明，复合物I中的DNAPKcs在复合物II的组装中发挥了重要作用。从复合物I到复合物II的逐步交换依赖于DNA-PK和聚（ADP-核糖）聚合酶对Zic 2的磷酸化。磷酸化的Zic 2蛋白与RNA解旋酶A形成稳定的复合物，复合物II可与RNA聚合酶II相互作用。磷酸化依赖的转化Zic 2含有分子复合物可能发生在转录调控。
The Zic family of zinc finger proteins is essential for animal development, as demonstrated by the holoprosencephaly caused by mammalian Zic2 mutation. To determine the molecular mechanism of Zic-mediated developmental control, we characterized two types of high molecular weight complexes, including Zic2. Complex I was composed of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), Ku70/80, and poly(ADP-ribose) polymerase; complex II contained Ku70/80 and RNA helicase A; all the components interacted directly with Zic2 protein. Immunoprecipitation, submiclear localization, and in vitro phosphorylation analyses revealed that the DNAPKcs in complex I played an essential role in the assembly of complex II. Stepwise exchange from complex I to complex II depended on phosphorylation of Zic2 by DNA-PK and poly(ADP-ribose) polymerase. Phosphorylated Zic2 protein made a stable complex with RNA helicase A, and complex II could interact with RNA polymerase II. Phosphorylation-dependent transformation of Zic2-containing molecular complexes may occur in transcriptional regulation.