2015年2月1日訊 /生物谷BIOON/ --近日,美國一研究小組在著名國際期刊Nature Cell Biology發表文章,他們發現parkin和USP30能夠通過泛素化過程平衡調控線粒體自噬,了解這一過程對開發治療帕金森疾病的藥物具有重要意義。
許多研究表明,線粒體功能紊亂在帕金森病的發病過程中發揮重要作用。Christian N. Cunningham等人通過實驗證實具有E3泛素連接酶功能的parkin和具有去泛素化酶功能的USP30能夠平衡調節線粒體自噬過程。他們發現,線粒體損傷能夠刺激parkin將lys6,lys11和lys63泛素鏈連接到線粒體上,而USP30能夠通過其去泛素化酶功能移除線粒體上的lys6-和lys11-泛素鏈,利用質譜技術,研究人員發現重組USP30會優先移除完整線粒體上的lys-6和lys11-泛素鏈,抵消parkin調節的泛素鏈形成過程。
綜上所述,該文章的結果表明細胞內線粒體的穩態會受到泛素化和去泛素化的平衡調控,這兩個過程的失衡是導致帕金森疾病發生的重要機理。這一研究結果或為我們揭示了細胞內的細胞器發生自噬過程的普遍性機制。(生物谷Bioon.com)
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USP30 and parkin homeostatically regulate atypical ubiquitin chains on mitochondria
Christian N. Cunningham, Joshua M. Baughman, Lilian Phu, Joy S. Tea, Christine Yu,Mary Coons, Donald S. Kirkpatrick, Baris Bingol & Jacob E. Corn
Multiple lines of evidence indicate that mitochondrial dysfunction is central to Parkinson's disease. Here we investigate the mechanism by which parkin, an E3 ubiquitin ligase, and USP30, a mitochondrion-localized deubiquitylase, regulate mitophagy. We find that mitochondrial damage stimulates parkin to assemble Lys 6, Lys 11 and Lys 63 chains on mitochondria, and that USP30is a ubiquitin-specific deubiquitylase with a strong preference for cleaving Lys 6- and Lys 11-linked multimers. Using mass spectrometry, we show that recombinant USP30 preferentially removes these linkage types from intact ubiquitylated mitochondria and counteracts parkin-mediated ubiquitin chain formation in cells. These results, combined with a series of chimaera and localization studies, afford insights into the mechanism by which a balance of ubiquitylation and deubiquitylation regulates mitochondrial homeostasis, and suggest a general mechanism for organelle autophagy.