title: Reconstitution of dynamic microtubules with Drosophila XMAP215, EB1, and Sentin.
abstract: Dynamic microtubules (MTs) are essential for various intracellular events, such as mitosis. In Drosophila melanogaster S2 cells, three MT tip-localizing proteins, Msps/XMAP215, EB1, and Sentin (an EB1 cargo protein), have been identified as being critical for accelerating MT growth and promoting catastrophe events, thus resulting in the formation of dynamic MTs. However, the molecular activity of each protein and the basis of the modulation of MT dynamics by these three factors are unknown. In this paper, we showed in vitro that XMAP215(msps) had a potent growth-promoting activity at a wide range of tubulin concentrations, whereas Sentin, when recruited by EB1 to the growing MT tip, accelerated growth and also increased catastrophe frequency. When all three factors were combined, the growth rate was synergistically enhanced, and rescue events were observed most frequently, but frequent catastrophes restrained the lengthening of the MTs. We propose that MT dynamics are promoted by the independent as well as the cooperative action of XMAP215(msps) polymerase and the EB1-Sentin duo.
authors.affiliation: Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Li
authors.forename: Takashi
authors.initials: T
authors.lastname: Moriwaki
authors.forename: Tomomi
authors.initials: T
authors.lastname: Tani
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Kozo
authors.initials: K
authors.lastname: Kaibuchi
authors.forename: Gohta
authors.initials: G
authors.lastname: Goshima
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D018411:Spodoptera / Q000166:cytology
chemical_list: D029721:Drosophila Proteins; C405804:EB1 microtubule binding proteins; D008869:Microtubule-Associated Proteins; C561110:Ssp2 protein, Drosophila; C121511:msps protein, Drosophila