Nuclear localization sequence of FUS and induction of stress granules by ALS mutants.
Nuclear localization sequence of FUS and induction of stress granules by ALS mutants.
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DOI：
10.1016/j.neurobiolaging.2010.06.010
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发表时间：
2011-12
影响因子：
4.2
通讯作者：
Zhu H
中科院分区：
文献类型：
--
作者：
Gal J;Zhang J;Kwinter DM;Zhai J;Jia H;Jia J;Zhu H
据报道，FUS的突变会导致一部分家族性肌萎缩侧索硬化（ALS）病例。野生型FUS主要定位于神经元的细胞核，但ALS突变体部分错误定位于细胞质并可形成包涵体。对于FUS亚细胞定位的调控以及ALS突变如何改变FUS功能，我们知之甚少。在此我们证明，FUS的C末端32个氨基酸残基构成一个有效的核定位序列（NLS），因为它可将β -半乳糖苷酶（LacZ，116 kDa）靶向细胞核。NLS的缺失或其中的ALS点突变会导致FUS在细胞质中错误定位。此外，我们鉴定出多聚A结合蛋白（PABP1），一种应激颗粒标记物，是FUS的相互作用伙伴。PABP1形成大的细胞质聚集体，与突变的FUS包涵体共定位。在野生型FUS存在的情况下，未观察到类似应激颗粒的这种聚集体。此外，与应激颗粒功能相关的加工体与突变的FUS包涵体相邻，但不共定位。我们的结果表明，FUS的C末端NLS中的ALS突变可损害FUS的核定位，并诱导细胞质错误定位、包涵体形成以及潜在的RNA代谢紊乱。
Mutations in FUS have been reported to cause a subset of familial amyotrophic lateral sclerosis (ALS) cases. Wild-type FUS is mostly localized in the nuclei of neurons, but the ALS mutants are partly mislocalized in the cytoplasm and can form inclusions. Little is known about the regulation of FUS subcellular localization or how the ALS mutations alter FUS function. Here we demonstrate that the C-terminal 32 amino acid residues of FUS constitute an effective nuclear localization sequence (NLS) as it targeted beta-galactosidase (LacZ, 116 kDa) to the nucleus. Deletion of or the ALS point mutations within the NLS caused cytoplasmic mislocalization of FUS. Moreover, we identified the poly-A binding protein (PABP1), a stress granule marker, as an interacting partner of FUS. PABP1 formed large cytoplasmic foci that co-localized with the mutant FUS inclusions. No such foci, which resemble stress granules, were observed in the presence of wild-type FUS. In addition, processing bodies, which are functionally related to stress granules, were adjacent to but not co-localized with the mutant FUS inclusions. Our results suggest that the ALS mutations in the C-terminal NLS of FUS can impair FUS nuclear localization and induce cytoplasmic mislocalization, inclusion formation, and potential perturbation of RNA metabolism.