S-Nitrosylation of DRP1 does not affect enzymatic activity and is not specific to Alzheimer's disease.
S-Nitrosylation of DRP1 does not affect enzymatic activity and is not specific to Alzheimer's disease.
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DOI：
10.3233/jad-2010-100552
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Bossy-Wetzel E
中科院分区：
文献类型：
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作者：
Bossy B;Petrilli A;Klinglmayr E;Chen J;Lütz-Meindl U;Knott AB;Masliah E;Schwarzenbacher R;Bossy-Wetzel E
线粒体功能障碍和突触丧失是与阿尔茨海默病 (AD) 相关的最早事件之一，可能在疾病的发作和进展中发挥致病作用。 AD 中线粒体和突触功能障碍的潜在机制仍不清楚。我们之前报道过一氧化氮 (NO) 会触发持续的线粒体裂变并导致神经元细胞死亡。最近的一篇文章声称，动力相关蛋白 1 (DRP1) 在半胱氨酸 644 处的 S-亚硝基化会导致蛋白质二聚化并增加 GTP 酶活性，并且是 AD 中 NO 诱导的线粒体裂变和神经元损伤的机制，但在帕金森病 (PD) 中则不然。然而，这份报告仍然存在争议。为了解决这一争议，我们研究了 S-亚硝基化对 DRP1 结构和功能的影响。与之前的报告相反，DRP1 的 S-亚硝基化不会增加 GTPase 活性或引起二聚化。事实上，DRP1在天然条件下并不以二聚体的形式存在，而是以四聚体的形式存在，能够在核苷酸结合后自组装成更高阶的螺旋状和环状寡聚结构。生物素开关测定证实，S-亚硝基化对 DRP1 寡聚化没有影响。重要的是，我们发现年龄匹配的正常人、AD 或 PD 患者大脑中 S-亚硝基化 DRP1 (SNO-DRP1) 水平没有显着差异。我们还发现 S-亚硝基化并不是 DRP1 所特有的，因为 S-亚硝基化视神经萎缩 1 (SNO-OPA1) 在所有人脑样本中都以相当的水平存在。最后，我们发现 NO 会触发 DRP1 在丝氨酸 616 处的磷酸化，从而导致其激活并招募到线粒体。我们的数据表明 AD 中亚硝化应激诱导的线粒体断裂的机制不是 DRP1 S-亚硝基化。
Mitochondrial dysfunction and synaptic loss are among the earliest events linked to Alzheimer's disease (AD) and might play a causative role in disease onset and progression. The underlying mechanisms of mitochondrial and synaptic dysfunction in AD remain unclear. We previously reported that nitric oxide (NO) triggers persistent mitochondrial fission and causes neuronal cell death. A recent article claimed that S-nitrosylation of dynamin related protein 1 (DRP1) at cysteine 644 causes protein dimerization and increased GTPase activity and is the mechanism responsible for NO-induced mitochondrial fission and neuronal injury in AD, but not in Parkinson's disease (PD). However, this report remains controversial. To resolve the controversy, we investigated the effects of S-nitrosylation on DRP1 structure and function. Contrary to the previous report, S-nitrosylation of DRP1 does not increase GTPase activity or cause dimerization. In fact, DRP1 does not exist as a dimer under native conditions, but rather as a tetramer capable of self-assembly into higher order spiral- and ring-like oligomeric structures after nucleotide binding. S-nitrosylation, as confirmed by the biotin-switch assay, has no impact on DRP1 oligomerization. Importantly, we found no significant difference in S-nitrosylated DRP1 (SNO-DRP1) levels in brains of age-matched normal, AD, or PD patients. We also found that S-nitrosylation is not specific to DRP1 because S-nitrosylated optic atrophy 1 (SNO-OPA1) is present at comparable levels in all human brain samples. Finally, we show that NO triggers DRP1 phosphorylation at serine 616, which results in its activation and recruitment to mitochondria. Our data indicate the mechanism underlying nitrosative stress-induced mitochondrial fragmentation in AD is not DRP1 S-nitrosylation.