DEPHOSPHORYLATION OF MICROTUBULE-BINDING SITES AT THE NEUROFILAMENT-H TAIL DOMAIN BY ALKALINE, ACID, AND PROTEIN PHOSPHATASES
DEPHOSPHORYLATION OF MICROTUBULE-BINDING SITES AT THE NEUROFILAMENT-H TAIL DOMAIN BY ALKALINE, ACID, AND PROTEIN PHOSPHATASES
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DOI：
10.1093/oxfordjournals.jbchem.a124107
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发表时间：
1993-06-01
影响因子：
2.7
通讯作者：
KISHIMOTO, T
中科院分区：
文献类型：
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作者：
HISANAGA, S;YASUGAWA, S;KISHIMOTO, T
利用几种磷酸酶研究了去磷酸化诱导的神经丝（NFs）与微管（MTs）的相互作用。大肠杆菌碱性磷酸酶和小麦胚芽酸性磷酸酶通过去磷酸化提高NF-H和NF-M的电泳迁移率，诱导NF-H与MTs结合，而碱性磷酸酶仅在NF-H的电泳迁移率接近完全去磷酸化水平时才观察到NF-H与MTs的结合。当NF-H开始与mt结合时，通过测量与NF-H结合的磷酸盐来估计剩余的磷酸盐数量。即使用碱性磷酸酶除去51个磷酸盐中的40个，NF-H也不能与MTs结合。另外6个磷酸的去除最终导致NF-H与MTs结合。用酸性磷酸酶也得到了类似的发现，即NF-H尾部区域的受限磷酸化位点，而不是磷酸盐的总量，对与MTs结合很重要。与碱性和酸性磷酸酶相比，四类蛋白磷酸酶（蛋白磷酸酶1、2A、2B和2C）对转移NF蛋白的电泳迁移和诱导NF与MTs的关联无效。
The dephosphorylation-induced interaction of neurofilaments (NFs) with microtubules (MTs) was investigated by using several phosphatases. Escherichia coli alkaline and wheat germ acid phosphatases increased the electrophoretic mobility of NF-H and NF-M by dephosphorylation, and induced the binding of NF-H to MTs. The binding of NFs to MTs was observed only after the electrophoretic mobility of NF-H approached the exhaustively dephosphorylated level when alkaline phosphatase was used. The number of phosphate remaining when NF-H began to bind to MTs was estimated by measuring phosphate bound to NF-H. NF-H did not bind to MTs even when about 40 phosphates from the total of 51 had been removed by alkaline phosphatase. The removal of 6 further phosphates finally resulted in the association of NF-H with MTs. A similar finding, that the restricted phosphorylation sites in the NF-H tail domain, but not the total amount of phosphates, were important for binding to MTs, was also obtained with acid phosphatase. In contrast to alkaline and acid phosphatases, four classes of protein phosphatases (protein phosphatases 1, 2A, 2B, and 2C) were ineffective for shifting the electrophoretic mobility of NF proteins and for inducing the association of NFs to MTs.