The `assembly‐promoting sequence region' of microtubule‐associated protein 4 failed to promote microtubule assembly

FEBS Letters

Katsuki, Miho¹  Kotani, Susumu¹  Murofushi, Hiromu²  Nakagawa, Hiroyuki¹  Tokuraku, Kiyotaka¹ 

[1] Department of Biochemical Engineering and Science, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka-shi 820, Japan;Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

关键词: Microtubule;    Microtubule-associated protein 4;    Tau;    Microtubule-associated protein 2;    MAP;    microtubule-associated protein;    AP;    assembly-promoting;    PMSF;    phenylmethylsulfonyl fluoride;    MES;    2-morpholinoethanesulfonic acid;    RB;    reassembly buffer;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(97)01342-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In order to study the function of the bovine MAP4 microtubule-binding domain (the assembly-promoting (AP) sequence region), a fragment corresponding to the AP sequence region was prepared using an Escherichia coli expression system. When the fragment was mixed with purified tubulin at 37°C, the fragment caused a time- and dose-dependent turbidity increase, and the fragment bound to tubulin. However, the products were cold-stable, and amorphous aggregates were observed by electron microscopy. Using axonemes as the seeds for microtubule assembly, the microtubule-elongating activity of the fragment was examined. A dose-dependent turbidity increase of the sample was observed, and electron microscopic observation revealed that microtubules were dose-dependently elongated from the axonemes. Consequently, the AP sequence region does not nucleate microtubules, but elongates them.

【 授权许可】

Unknown