The nitric oxide-cyclic GMP pathway regulates FoxO and alters dopaminergic neuron survival in Drosophila.
The nitric oxide-cyclic GMP pathway regulates FoxO and alters dopaminergic neuron survival in Drosophila.
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DOI：
10.1371/journal.pone.0030958
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Imai Y
中科院分区：
文献类型：
--
作者：
Kanao T;Sawada T;Davies SA;Ichinose H;Hasegawa K;Takahashi R;Hattori N;Imai Y
叉头框转录因子FoxO的激活被认为参与了帕金森病（PD）果蝇模型中的多巴胺能（DA）神经变性，其中PD基因产物LRRK 2通过磷酸化激活FoxO。在目前的研究中，结合果蝇遗传学和生化分析，我们表明，环鸟苷一磷酸（cGMP）依赖性激酶II（cGKII）也磷酸化FoxO在相同的残基LRRK 2，和果蝇直系同源物的cGKII和LRRK 2，DG 2/For和dLRRK，分别增强FoxO的神经毒性活性的添加剂的方式。使用哺乳动物cGKII和FoxO 1的生物化学测定显示，cGKII通过FoxO 1 S319位点的磷酸化以与LRRK 2相同的方式增强FoxO 1的转录活性。果蝇FoxO突变体对DG 2和dLRRK的磷酸化具有抗性（dFoxO S259 A对应于人FoxO 1 S319 A），其抑制了由FoxO和DG 2的共表达引起的神经毒性并改善了运动功能障碍。一氧化氮合酶（NOS）和可溶性鸟苷酸环化酶（sGC）也增加了FoxO的活性，而NOS抑制剂L-NAME的管理抑制了共同表达FoxO和DG 2的老年果蝇中DA神经元的损失。这些结果强烈表明，NO-FoxO轴有助于LRRK 2相关PD中的DA神经变性。
Activation of the forkhead box transcription factor FoxO is suggested to be involved in dopaminergic (DA) neurodegeneration in a Drosophila model of Parkinson's disease (PD), in which a PD gene product LRRK2 activates FoxO through phosphorylation. In the current study that combines Drosophila genetics and biochemical analysis, we show that cyclic guanosine monophosphate (cGMP)-dependent kinase II (cGKII) also phosphorylates FoxO at the same residue as LRRK2, and Drosophila orthologues of cGKII and LRRK2, DG2/For and dLRRK, respectively, enhance the neurotoxic activity of FoxO in an additive manner. Biochemical assays using mammalian cGKII and FoxO1 reveal that cGKII enhances the transcriptional activity of FoxO1 through phosphorylation of the FoxO1 S319 site in the same manner as LRRK2. A Drosophila FoxO mutant resistant to phosphorylation by DG2 and dLRRK (dFoxO S259A corresponding to human FoxO1 S319A) suppressed the neurotoxicity and improved motor dysfunction caused by co-expression of FoxO and DG2. Nitric oxide synthase (NOS) and soluble guanylyl cyclase (sGC) also increased FoxO's activity, whereas the administration of a NOS inhibitor L-NAME suppressed the loss of DA neurons in aged flies co-expressing FoxO and DG2. These results strongly suggest that the NO-FoxO axis contributes to DA neurodegeneration in LRRK2-linked PD.