NAD+ analog reveals PARP-1 substrate-blocking mechanism and allosteric communication from catalytic center to DNA-binding domains
NAD+ analog reveals PARP-1 substrate-blocking mechanism and allosteric communication from catalytic center to DNA-binding domains
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DOI：
10.1038/s41467-018-03234-8
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发表时间：
2018-02-27
影响因子：
16.6
通讯作者：
Pascal, John M.
中科院分区：
文献类型：
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作者：
Langelier, Marie-France;Zandarashvili, Levani;Pascal, John M.
PARP-1裂解NAD(+)，并将生成的ADP-核糖部分转移到目标蛋白和后续的ADP-核糖聚合物上。变构网络将PARP-1多域DNA损伤的检测与催化结构域的结构变化联系起来，从而解除催化自抑制；然而，自抑制的机制尚不清楚。在这里，我们证明了使用非水解性NAD(+)类似物苯甲酰胺腺嘌呤二核苷酸(BAD)，PARP-1的自身抑制是由于选择性地阻断NAD(+)结合而产生的。在检测到DNA损伤后，与催化域的不良结合导致远距离DNA结合表面的PARP-1动力学改变，导致对DNA损伤的亲和力增加，并提供了反向变构的直接证据。我们的发现揭示了在DNA断裂时激活PARP-1然后稳定PARP-1的两步机制，表明PARP-1变构影响DNA损伤的持久性，并对与NAD(+)结合位点结合的PARP抑制剂具有重要意义。
PARP-1 cleaves NAD(+) and transfers the resulting ADP-ribose moiety onto target proteins and onto subsequent polymers of ADP-ribose. An allosteric network connects PARP-1 multidomain detection of DNA damage to catalytic domain structural changes that relieve catalytic autoinhibition; however, the mechanism of autoinhibition is undefined. Here, we show using the non-hydrolyzable NAD(+) analog benzamide adenine dinucleotide (BAD) that PARP-1 autoinhibition results from a selective block on NAD(+) binding. Following DNA damage detection, BAD binding to the catalytic domain leads to changes in PARP-1 dynamics at distant DNA-binding surfaces, resulting in increased affinity for DNA damage, and providing direct evidence of reverse allostery. Our findings reveal a two-step mechanism to activate and to then stabilize PARP-1 on a DNA break, indicate that PARP-1 allostery influences persistence on DNA damage, and have important implications for PARP inhibitors that engage the NAD(+) binding site.