TMBP200, a microtubule bundling polypeptide isolated from telophase tobacco BY-2 cells is a MOR1 homologue.
Bundles of microtubules and cross-bridges between microtubules in the bundles have been observed in phragmoplasts, but proteins responsible for forming the cross-bridges have not been identified. We isolated TMBP200, a novel microtubule bundling polypeptide with an estimated relative molecular mass of about 200,000 from telophase tobacco BY-2 cells. Ultrastructural observation of microtubules bundled by purified TMBP200 in vitro revealed that TMBP200 forms cross-bridges between microtubules. The structure of the bundles and lengths of the cross-bridges were quite similar to those observed in phragmoplasts, suggesting that TMBP200 participates in the formation of microtubule bundles in phragmoplasts. The cDNA encoding TMBP200 was cloned and the deduced amino acid sequence showed homology to a class of microtubule-associated proteins including Xenopus XMAP215, human TOGp and Arabidopsis MOR1.
Yasuhara
Hiroki
H
Department of Biotechnology, Faculty of Engineering, Kansai University, Yamate-cho, Suita, Osaka, 564-8680 Japan. yasuhara@ipcku.kansai-u.ac.jp
Muraoka
Masaaki
M
Shogaki
Hiroki
H
Mori
Hitoshi
H
Sonobe
Seiji
S
D000595:Amino Acid Sequence; D000818:Animals; D029681:Arabidopsis Proteins; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D006801:Humans; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D013692:Telophase / Q000502:physiology; D014026:Nicotiana / Q000166:cytology / Q000235:genetics* / Q000648:ultrastructure
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; C429183:MOR1 protein, Arabidopsis; D008869:Microtubule-Associated Proteins; D010940:Plant Proteins