CLASP modulates microtubule-cortex interaction during self-organization of acentrosomal microtubules.
CLASP proteins associate with either the plus ends or sidewalls of microtubules depending on the subcellular location and cell type. In plant cells, CLASP's distribution along the full length of microtubules corresponds with the uniform anchorage of microtubules to the cell cortex. Using live cell imaging, we show here that loss of CLASP in Arabidopsis thaliana results in partial detachment of microtubules from the cortex. The detached portions undergo extensive waving, distortion, and changes in orientation, particularly when exposed to the forces of cytoplasmic streaming. These deviations from the normal linear polymerization trajectories increase the likelihood of intermicrotubule encounters that are favorable for subsequent bundle formation. Consistent with this, cortical microtubules in clasp-1 leaf epidermal cells are hyper-parallel. On the basis of these data, we identify a novel mechanism where modulation of CLASP activity governs microtubule-cortex attachment, thereby contributing to self-organization of cortical microtubules.
Ambrose
J Christian
JC
The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Wasteneys
Geoffrey O
GO
D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018385:Centrosome / Q000378:metabolism*; D018548:Cotyledon / Q000166:cytology / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000172:deficiency / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D019441:Plant Epidermis / Q000166:cytology / Q000378:metabolism
D029681:Arabidopsis Proteins; C527272:CLASP protein, Arabidopsis; D008869:Microtubule-Associated Proteins