18 kDa microtubule‐associated protein: identification as a new light chain (LC‐3) of microtubule‐associated protein 1 (MAP‐1)

FEBS Letters

Gelfand, Vladimir I.¹  Kuznetsov, Sergei A.² 

[1] A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, Moscow 119899, USSR;Department of Molecular Biology, Faculty of Biology Moscow State University, Moscow 119899, USSR

关键词: Microtubule;    Microtubule-associated protein 1;    Immunoprecipitation;    MAP;    microtubule-associated protein;    LC-1;    LC-2 and LC-3;    light chains 1;    2 and 3 of MAP-1;   

DOI  :  10.1016/0014-5793(87)81574-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

SDS gel electrophoresis of microtubule proteins obtained from bovine brain by polymerization cycles revealed a new protein of 18 kDa. This protein was copolymerized with tubulin and its stoichiometry to tubulin remained constant for at least 5 cycles of assembly. Moreover, this protein remained bound to microtubules stabilized with 10 μM taxol and pelleted through a 4 M glycerol cushion. The same 18 kDa protein was found in a purified preparation of the high molecular mass microtubule-associated protein 1 (MAP-1). The 18 kDa protein copurified with the MAP-1 heavy chains during column chromatography on phosphocellulose, DEAE-cellulose, hydroxyapatite and Bio-Gel A-15m. Incubation of the MAP-1 preparation with a mouse monoclonal antibody to the light chain 1 (LC-1) of MAP-1 and with a second precipitating antibody (a rabbit antibody to mouse IgG) immunoprecipitated from the solution all the known components of MAP-1 (heavy chains, LC-1, LC-2), as well as the 18 kDa protein. Immunoblotting showed, however, that this antibody does not interact directly with the 18 kDa protein. These results indicate that the 18 kDa protein forms a complex with all other components of MAP-1. This polypeptide, therefore, is a new light chain (LC-3) of M AP-1.

【 授权许可】

Unknown