Aggregate formation and phosphorylation of neurofilament-L Pro22 Charcot-Marie-Tooth disease mutants
Aggregate formation and phosphorylation of neurofilament-L Pro22 Charcot-Marie-Tooth disease mutants
复制标题
DOI：
10.1093/hmg/ddl011
复制
发表时间：
2006-03-15
影响因子：
3.5
通讯作者：
Hisanaga, SI
中科院分区：
文献类型：
--
作者：
Sasaki, T;Gotow, T;Hisanaga, SI
夏科-玛丽-图斯病(CMT)是最常见的遗传性周围神经疾病。轴索型CMT2E的致病基因已被鉴定为神经丝轻链(NF-L)。通过培养细胞和体外实验，我们分析了Pro22CMT突变型蛋白的纤丝形成能力，包括NF-L、P22S和P22T。在体外，NF-L Pro22突变体蛋白在SW13-细胞和皮质神经元中形成大的聚集体，并组装成细于10 nm的短丝。这些线在其末端相互关联并缠绕成大的聚集体，也是异常的，在低聚物形成的步骤中被检测到。Pro22基因突变使细胞周期蛋白依赖性蛋白激酶5和外部信号调节蛋白激酶抑制Thr21的磷酸化，从而抑制了微丝的组装，但蛋白激酶A(PKA)的磷酸化抑制了体外聚集的形成，并减轻了皮质神经元的聚集。这些结果表明，Pro22CMT突变通过破坏适当的寡聚体的形成而诱导异常的微丝聚集，并通过与PKA的磷酸化来缓解聚集，这使得它成为治疗的一个可行的靶点。
Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral nerve disorder. The causative gene for axonal type CMT2E has been identified as neurofilament light (NF-L) chain. Using cultured cells and in vitro assays, we analyzed the filament formation ability of Pro22 CMT mutant proteins of NF-L, P22S and P22T. NF-L Pro22 mutant proteins formed large aggregates in SW13- cells and cortical neurons and assembled into short twisty threads thinner than 10 nm filaments in vitro. Those threads associated with each other at their ends and entangled into large aggregates, also abnormalities, were detected at steps in oligomer formation. Pro22 mutations abolished Thr21 phosphorylation by cyclin-dependent kinase 5 and external signal regulated kinase, which suppressed filament assembly, but phosphorylation by protein kinase A (PKA) inhibited aggregate formation in vitro and alleviated aggregates in cortical neurons. These results indicate that the Pro22 CMT mutation induces abnormal filament aggregates by disrupting proper oligomer formation and the aggregates are mitigated by phosphorylation with PKA, which makes it a viable target for the development for therapeutics.