RNA-binding protein TLS is a major nuclear aggregate-interacting protein in huntingtin exon 1 with expanded polyglutamine-expressing cells
RNA-binding protein TLS is a major nuclear aggregate-interacting protein in huntingtin exon 1 with expanded polyglutamine-expressing cells
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DOI：
10.1074/jbc.m705306200
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发表时间：
2008-03-07
影响因子：
4.8
通讯作者：
Nukina, Nobuyuki
中科院分区：
文献类型：
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作者：
Doi, Hiroshi;Okamura, Kazumasa;Nukina, Nobuyuki
细胞内聚集物的形成是多聚谷氨酰胺(PolyQ)疾病的标志。我们用质谱仪分析了纯化的核多Q聚集体的组成。因此，我们发现在脂肪肉瘤中转位的RNA结合蛋白(TLS)是亨廷顿病细胞模型中核多聚Q聚集相互作用蛋白的主要成分之一，也与R6/2小鼠的神经元核内包涵体有关。体外研究表明，TLS可以直接与截短的N-末端亨廷顿蛋白(TNhtt)聚集体结合，但不能与18、42或62Q的单体GST-tNhtt结合，表明tNhtt蛋白在形成聚集体后获得了隔离TLS的能力。硫代黄素T试验和电子显微镜研究进一步支持了TLS在tNhtt-42Q淀粉样蛋白形成早期就与tNhtt-42Q聚集体结合的观点。免疫组织化学结果显示，TLS与亨廷顿病脑组织中的神经元核内包涵体有关。由于TLS具有多种功能，TLS与多Q聚合体的隔离可能在多Q疾病患者脑内的多种病理变化中发挥作用。
Formation of intracellular aggregates is the hallmark of polyglutamine (polyQ) diseases. We analyzed the components of purified nuclear polyQ aggregates by mass spectrometry. As a result, we found that the RNA-binding protein translocated in liposarcoma (TLS) was one of the major components of nuclear polyQ aggregate-interacting proteins in a Huntington disease cell model and was also associated with neuronal intranuclear inclusions of R6/2 mice. In vitro study revealed that TLS could directly bind to truncated N-terminal huntingtin (tNhtt) aggregates but could not bind to monomer GST-tNhtt with 18, 42, or 62Q, indicating that the tNhtt protein acquired the ability to sequester TLS after forming aggregates. Thioflavin T assay and electron microscopic study further supported the idea that TLS bound to tNhtt-42Q aggregates at the early stage of tNhtt-42Q amyloid formation. Immunohistochemistry showed that TLS was associated with neuronal intranuclear inclusions of Huntington disease human brain. Because TLS has a variety of functional roles, the sequestration of TLS to polyQ aggregates may play a role in diverse pathological changes in the brains of patients with polyQ diseases.