MICROHETEROGENEITY OF MICROTUBULE-ASSOCIATED TAU-PROTEINS IS DUE TO DIFFERENCES IN PHOSPHORYLATION
MICROHETEROGENEITY OF MICROTUBULE-ASSOCIATED TAU-PROTEINS IS DUE TO DIFFERENCES IN PHOSPHORYLATION
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DOI：
10.1111/j.1471-4159.1986.tb00788.x
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发表时间：
1986-11-01
影响因子：
4.7
通讯作者：
SHELANSKI, ML
中科院分区：
文献类型：
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作者：
BUTLER, M;SHELANSKI, ML
我们已经研究了微管相关的异质性。使用τ-特异性抗体和双向电泳。针对τ的单克隆抗体和多克隆抗体两者。蛋白质识别在十二烷基硫酸钠（SDS）-聚丙烯酰胺凝胶上电泳的牛脑微管蛋白质中的五条带，表观分子量在56，000和66，000之间。在二维凝胶上分离的牛脑微管的免疫印迹，在第一维中使用非平衡pH梯度电泳，在第二维中使用SDS-凝胶电泳，揭示了> 30种同种型的τ。存在.该. tau。蛋白质的pI从6.5到8.5不等，高分子量形式的酸性更强。τ的微观异质性不是由微管的循环诱导的，因为τ的二维免疫印迹显示，与τ的几乎相同。来自循环小管。成年大鼠脑τ，其在SDS凝胶上显示为三个双峰带，也显示出相当大的等电不均一性，τ也是如此。从7日龄大鼠，这似乎只有一个带在SDS凝胶。牛脑去磷酸化后。用碱性磷酸酶，SDS凝胶上的最高分子量条带消失。在二维凝胶上，τ的数目是变体在去磷酸化后减少一半以上，并且更碱性的种类在强度上大大增加。用. τ进行的初步实验在体内用32 PO 4标记也表明酸性越强的τ。蛋白质是更高度磷酸化的形式。因此，τ的等电异质性。蛋白质存在于所有年龄，并且至少部分是由于tau的磷酸化状态的差异。同种型。
We have studied the heterogeneity of the microtubule-associated .tau. proteins using .tau.-specific antibodies and two-dimensional electrophoresis. Both monoclonal and polyclonal antibodies to .tau. proteins recognize five bands in cow brain microtubule proteins run on sodium dodecyl sulfate (SDS)-polyacrylamide gels, with apparent molecular weights between 56,000 and 66,000. Immunoblots of cow brain microtubules separated on two-dimensional gels, using nonequilibrium pH gradient electrophoresis in the first dimension and SDS-gel electrophoresis in the second, reveal that > 30 isoforms of .tau. exist. The .tau. proteins vary in pI from 6.5 to 8.5, with the higher-molecular weight forms being more acidic. The microheterogeneity of .tau. is not induced by cycling of microtubules, because two-dimensional immunoblots of .tau. from total brain are almost identical to those of .tau. from cycled tubules. Adult rat brain .tau., which appears as three doublet bands on SDS gels, also exhibits considerable isoelectric heterogeneity, as does .tau. from 7-day-old rats, which appears as only one band on SDS gels. After dephosphorylation of cow brain .tau. with alkaline phosphatase, the highest-molecular-weight band disappears on SDS gels. On two-dimensional gels, the number of .tau. variants decreases by more than half after dephosphorylation, and the more basic species increase greatly in intensity. Preliminary experiments with .tau. labeled in vivo with 32PO4 also indicate that the more acidic .tau. proteins are the more highly phosphorylated forms. Thus, isoelectric heterogeneity of .tau. proteins exists at all ages and is due, at least in part, to differences in the state of phosphorylation of .tau. isoforms.