Fujii T, Watanabe M, Nakamura A
Department of Imagination Science and Technology (Kansei Engineering), Faculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Neurochem Int. 1996 May-Jun;28(5-6):535-44. doi: 10.1016/0197-0186(95)00128-x.
The microtubule-associated protein (MAP) 1 preparation, MAP1A and 1B, obtained from rat brain microtubules was associated with protein kinases that were insensitive to cAMP, cGMP, calcium, calcium/calmodulin and calcium/phosphatidylserine. The fractionation of highly purified MAP1 by phosphocellulose chromatography revealed that protein kinase activity to phosphorylate phosvitin was separated into three major peaks (MAP1 kinases A, B and C). MAP1 was recovered in the MAP1 kinase A fraction and phosphorylated by the contained kinase. MAP1 kinase A is a novel protein kinase that is remarkably activated by poly-L-lysine and poly-L-arginine, but very insensitive to heparin among the kinases. Photoaffinity labeling using [alpha-32P]8-azido ATP indicated that the 65 kDa polypeptide is identified as an ATP-binding protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the highly purified MAP1 and MAP1 kinase A fractions. MAP1 kinases B and C may be identified as casein kinase I- and II-like kinases. The present results show that MAP1 is associated with at least three kinases and provide an insight for understanding thoroughly the MAP1-mediated microtubule functions.
从大鼠脑微管中获得的微管相关蛋白（MAP）1制剂，即MAP1A和1B，与对环磷酸腺苷（cAMP）、环磷酸鸟苷（cGMP）、钙、钙/钙调蛋白以及钙/磷脂酰丝氨酸不敏感的蛋白激酶相关。通过磷酸纤维素色谱法对高度纯化的MAP1进行分级分离显示，使卵黄高磷蛋白磷酸化的蛋白激酶活性被分离为三个主要峰（MAP1激酶A、B和C）。MAP1在MAP1激酶A级分中回收，并被其中所含的激酶磷酸化。MAP1激酶A是一种新型蛋白激酶，在激酶中它被聚-L-赖氨酸和聚-L-精氨酸显著激活，但对肝素非常不敏感。使用[α-32P]8-叠氮基ATP进行光亲和标记表明，在高度纯化的MAP1和MAP1激酶A级分的十二烷基硫酸钠-聚丙烯酰胺凝胶电泳上，65 kDa多肽被鉴定为一种ATP结合蛋白。MAP1激酶B和C可能被鉴定为酪蛋白激酶I样和II样激酶。目前的结果表明，MAP1与至少三种激酶相关，并为深入理解MAP1介导的微管功能提供了线索。
