Assembly of tau in transgenic animals expressing P301L tau: alteration of phosphorylation and solubility
Assembly of tau in transgenic animals expressing P301L tau: alteration of phosphorylation and solubility
复制标题
DOI：
10.1046/j.1471-4159.2002.01241.x
复制
发表时间：
2002-12-01
影响因子：
4.7
通讯作者：
Yen, SH
中科院分区：
文献类型：
--
作者：
Sahara, N;Lewis, J;Yen, SH
对发生神经纤维变性并表达带有P301L错义突变的4个重复的人tau基因的转基因小鼠(JNPL3)进行了生化鉴定，以确定从可溶性tau到聚集态tau的发育是否涉及一个中间阶段。从不同年龄的小鼠的匀浆中分离出缓冲可溶(S1)、肌糖和盐可提取(S2)和肌糖不可溶颗粒(P3)组分，并分析了人tau的分布、磷酸化和细丝形成。S1和S2组分含有50-60 kDa的tau，而S2组分也含有-kDa tau。P3组分中tau含量随年龄增加而增加，并与可溶性tau含量呈正相关。2.5-6.5月龄小鼠的P3组分含有和50-60 kDa的tau，而8.5月龄及以上转基因动物的P3组分主要含有kDa和更高相对分子质量的tau。S2和P3组分中含有相当数量的-kDa tau。-kDa tau主要是人类的，并在多个位点被磷酸化：Thr181、Ser202/Thr205、Thr212、Thr231、Ser262、Ser396/Ser404、Ser409和Ser422。这些位点中的大多数在S2组分中的磷酸化程度低于在P3组分中。在3个月大的雌性JNPL3小鼠的P3组分中检测到了tau聚合物，但在非转基因对照组中没有检测到。结果表明，S2中的tau代表了不溶性tau的中间产物，磷酸化可能在微丝的形成和/或稳定中发挥作用。
Transgenic mice (JNPL3), which develop neurofibrillary degeneration and express four-repeat human tau with P301L missense mutation, were characterized biochemically to determine whether the development of aggregated tau from soluble tau involves an intermediate stage. Homogenates from mice of different ages were separated into buffer-soluble (S1), sarkosyl- and salt-extractable (S2) and sarkosyl-insoluble pellet (P3) fractions, and analyzed for human tau distribution, phosphorylation and filament formation. S1 and S2 fractions contained 50-60-kDa tau whereas the S2 fraction also had 64-kDa tau. The level of tau in the P3 fraction increased in an age-dependent manner and correlated positively with the soluble tau concentration. The P3 fraction from 2.5-6.5-month-old mice contained 64- and 50-60-kDa tau, whereas that from 8.5-month and older transgenic animals contained mostly 64-kDa and higher molecular weight tau. The S2 and P3 fractions contained comparable amounts of 64-kDa tau. The 64-kDa tau was predominantly human, and phosphorylated at multiple sites: Thr181, Ser202/Thr205, Thr212, Thr231, Ser262, Ser396/Ser404, Ser409 and Ser422. Most of these sites were phosphorylated to a lesser extent in S2 than in P3 fractions. Tau polymers were detected in P3 fractions from 3-month and older female JNPL3 mice, but not in non-transgenic controls. The results suggest that tau in S2 represents an intermediate from which insoluble tau is derived, and that phosphorylation may play a role in filament formation and/or stabilization.