Activation of the SNF2 Family ATPase ALC1 by Poly(ADP-ribose) in a Stable ALC1.PARP1.Nucleosome Intermediate
Activation of the SNF2 Family ATPase ALC1 by Poly(ADP-ribose) in a Stable ALC1.PARP1.Nucleosome Intermediate
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DOI：
10.1074/jbc.m112.401141
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发表时间：
2012-12-21
影响因子：
4.8
通讯作者：
Conaway, Ronald C.
中科院分区：
文献类型：
--
作者：
Gottschalk, Aaron J.;Trivedi, Rushi D.;Conaway, Ronald C.
人类 ALC1/CHD1L 癌基因编码 SNF2 家族 ATP 酶，其具有结合聚 (ADP-核糖) (PAR) 的大结构域。我们和其他人之前表明，ALC1 具有一种神秘的 ATP 依赖性核小体重塑活性，该活性在 PARP1 和 NAD(+)（其 PAR 合成的底物）存在时被有效激活。在这项工作中，我们剖析了 PARP1 和 NAD(+) 激活 ALC1 核小体重塑的机制。我们证明 ALC1 激活取决于稳定的 ALC1.PARylated PARP1.nucleosome 中间体的形成。此外，通过利用新型 PAR 足迹分析，我们获得了证据，表明在核小体重塑反应过程中，ALC1 宏结构域与自 PAR 化的 PARP1 上的 PAR 保持稳定相关。综上所述，我们的研究结果与 PAR 化的 PARP1 上存在的 PAR 作为 ALC1 核小体重塑活性的变构效应器的模型一致。
The human ALC1/CHD1L oncogene encodes an SNF2 family ATPase with a macrodomain that binds poly(ADP-ribose) (PAR). We and others previously showed that ALC1 possesses a cryptic ATP-dependent nucleosome remodeling activity that is potently activated in the presence of PARP1 and NAD(+), its substrate for PAR synthesis. In this work, we dissected the mechanism by which PARP1 and NAD(+) activate ALC1 nucleosome remodeling. We demonstrate that ALC1 activation depends on the formation of a stable ALC1.PARylated PARP1.nucleosome intermediate. In addition, by exploiting a novel PAR footprinting assay, we obtained evidence that the ALC1 macrodomain remains stably associated with PAR on autoPARylated PARP1 during the course of nucleosome remodeling reactions. Taken together, our findings are consistent with the model that PAR present on PARylated PARP1 acts as an allosteric effector of ALC1 nucleosome remodeling activity.