Sugimoto Yoshitaka, Takasaki Teruaki, Yamada Ryuga, Kurosaki Ryo, Yamane Tomonari, Sugiura Reiko
Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashiosaka, Japan.
Genes Cells. 2025 Jan;30(1):e13185. doi: 10.1111/gtc.13185.
Aggregation of alpha-synuclein (α-Syn) is implicated in the pathogenesis of several neurodegenerative disorders, such as Parkinson's disease and Dementia with Lewy bodies, collectively termed synucleinopathies. Thus, tremendous efforts are being made to develop strategies to prevent or inhibit α-Syn aggregation. Here, we genetically engineered fission yeast to express human α-Syn C-terminally fused to green fluorescent protein (GFP) at low and high levels. α-Syn was localized at the cell tips and septa at low-level expression. At high-level expression, α-Syn was observed to form cytoplasmic aggregates. Notably, rapamycin, a natural product that allosterically inhibits the mammalian target of rapamycin (mTOR) by forming a complex with FKBP12, and Torin1, a synthetic mTOR inhibitor that blocks ATP binding to mTOR, markedly reduced the number of cells harboring α-Syn aggregates. These mTOR inhibitors abrogate α-Syn aggregation without affecting α-Syn expression levels. Rapamycin, but not Torin1, failed to reduce α-Syn aggregation in the deletion cells of fkh1, encoding FKBP12, indicating the requirement of FKBP12 for rapamycin-mediated inhibition of α-Syn aggregation. Importantly, the effect of rapamycin was also observed in the cells lacking atg1, a key regulator of autophagy. Collectively, rapamycin abrogates human α-Syn aggregation expressed in fission yeast via an autophagy-independent mechanism mediated by FKBP12.
α-突触核蛋白（α-Syn）的聚集与几种神经退行性疾病的发病机制有关，如帕金森病和路易体痴呆，统称为突触核蛋白病。因此，人们正在付出巨大努力来开发预防或抑制α-Syn聚集的策略。在这里，我们对裂殖酵母进行基因工程改造，使其在低水平和高水平下表达C末端与绿色荧光蛋白（GFP）融合的人α-Syn。在低水平表达时，α-Syn定位于细胞尖端和隔膜处。在高水平表达时，观察到α-Syn形成细胞质聚集体。值得注意的是，雷帕霉素是一种天然产物，通过与FKBP12形成复合物来变构抑制哺乳动物雷帕霉素靶蛋白（mTOR），以及托林1，一种阻止ATP与mTOR结合的合成mTOR抑制剂，显著减少了含有α-Syn聚集体的细胞数量。这些mTOR抑制剂消除了α-Syn的聚集，而不影响α-Syn的表达水平。雷帕霉素而非托林1，在编码FKBP12的fkh1缺失细胞中未能减少α-Syn的聚集，这表明FKBP12是雷帕霉素介导的抑制α-Syn聚集所必需的。重要的是，在缺乏自噬关键调节因子atg1的细胞中也观察到了雷帕霉素的作用。总的来说，雷帕霉素通过由FKBP12介导的自噬非依赖性机制消除了裂殖酵母中表达的人α-Syn聚集。
