Self-organization of microtubule bundles in anucleate fission yeast cells.
Self-organization of cellular structures is an emerging principle underlying cellular architecture. Properties of dynamic microtubules and microtubule-binding proteins contribute to the self-assembly of structures such as microtubule asters. In the fission yeast Schizosaccharomyces pombe, longitudinal arrays of cytoplasmic microtubule bundles regulate cell polarity and nuclear positioning. These bundles are thought to be organized from the nucleus at multiple interphase microtubule organizing centres (iMTOCs). Here, we find that microtubule bundles assemble even in cells that lack a nucleus. These bundles have normal organization, dynamics and orientation, and exhibit anti-parallel overlaps in the middle of the cell. The mechanisms that are responsible for formation of these microtubule bundles include cytoplasmic microtubule nucleation, microtubule release from the equatorial MTOC (eMTOC), and the dynamic fusion and splitting of microtubule bundles. Bundle formation and organization are dependent on mto1p (gamma-TUC associated protein), ase1p (PRC1), klp2p (kinesin-14) and tip1p (CLIP-170). Positioning of nuclear fragments and polarity factors by these microtubules illustrates how self-organization of these bundles contributes to establishing global spatial order.
Daga
Rafael R
RR
Microbiology Department, Columbia University College of Physicians and Surgeons, 701 168th St., New York, NY 10032, USA.
Lee
Kyeng-Gea
KG
Bratman
Scott
S
Salas-Pino
Silvia
S
Chang
Fred
F
D002467:Cell Nucleus; D007399:Interphase; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D022101:Microtubule-Organizing Center / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D012568:Schizosaccharomyces / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus
D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins