title: Five factors can reconstitute all three phases of microtubule polymerization dynamics.
abstract: Cytoplasmic microtubules (MTs) undergo growth, shrinkage, and pausing. However, how MT polymerization cycles are produced and spatiotemporally regulated at a molecular level is unclear, as the entire cycle has not been recapitulated in vitro with defined components. In this study, we reconstituted dynamic MT plus end behavior involving all three phases by mixing tubulin with five Drosophila melanogaster proteins (EB1, XMAP215Msps, Sentin, kinesin-13Klp10A, and CLASPMast/Orbit). When singly mixed with tubulin, CLASPMast/Orbitstrongly inhibited MT catastrophe and reduced the growth rate. However, in the presence of the other four factors, CLASPMast/Orbitacted as an inducer of pausing. The mitotic kinase Plk1Polomodulated the activity of CLASPMast/Orbitand kinesin-13Klp10Aand increased the dynamic instability of MTs, reminiscent of mitotic cells. These results suggest that five conserved proteins constitute the core factors for creating dynamic MTs in cells and that Plk1-dependent phosphorylation is a crucial event for switching from the interphase to mitotic mode.
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.|Marine Biological Laboratory, Woods Hole, MA 02543.
authors: Takashi
authors: T
authors: Moriwaki
authors: Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan goshima@bio.nagoya-u.ac.jp.|Marine Biological Laboratory, Woods Hole, MA 02543.
authors: Gohta
authors: G
authors: Goshima
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism; D007700:Kinetics; D008870:Microtubules / Q000378:metabolism*; D010766:Phosphorylation; D058105:Polymerization; D011336:Probability; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D016547:Kinesins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1