Two Kinesin-14A Motors Oligomerize to Drive Poleward Microtubule Convergence for Acentrosomal Spindle Morphogenesis in Arabidopsis thaliana
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Le résumé fourni par la source
Plant cells form acentrosomal spindles with microtubules (MTs) converged toward two structurally undefined poles by employing MT minus end-directed Kinesin-14 motors. To date, it is unclear whether the convergent bipolar MT array assumes unified poles in plant spindles, and if so, how such a goal is achieved. Among six classes of Kinesin-14 motors in Arabidopsis thaliana, the Kinesin-14A motors ATK1 (KatA) and ATK5 share the essential function in spindle morphogenesis. To understand how the two functionally redundant Kinesin-14A motors contributed to the spindle assembly, we had ATK1-GFP and ATK5-GFP fusion proteins expressed in their corresponding null mutants and found that they were functionally comparable to their native forms. Although ATK1 was a nuclear protein and ATK5 cytoplasmic prior to nuclear envelop breakdown, at later mitotic stages, the two motors shared similar localization patterns of uniform association with both spindle and phragmoplast MTs. We found that ATK1 and ATK5 were rapidly concentrated toward unified polar foci when cells were under hyperosmotic conditions. Concomitantly, spindle poles became perfectly focused as if there were centrosome-like MT-organizing centers where ATK1 and ATK5 were highly enriched and at which kinetochore fibers pointed. The separation of ATK1/ATK5-highlighted MTs from those of kinetochore fibers suggested that the motors translocated interpolar MTs. Our protein purification and live-cell imaging results showed that ATK1 and ATK5 are associated with each other in vivo. The stress-induced spindle pole convergence was also accompanied by poleward accumulation of the MT nucleator γ-tubulin. These results led to the conclusion that the two Kinesin-14A motors formed oligomeric motor complexes that drove MT translocation toward the spindle pole to establish acentrosomal spindles with convergent poles.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Two Kinesin-14A Motors Oligomerize to Drive Poleward Microtubule Convergence for Acentrosomal Spindle Morphogenesis in Arabidopsis thaliana
- Date Crossref
- 22/07/2022
- Éditeur
- Frontiers Media SA
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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University of Michigan Department of Cell and Developmental Biology pays non établi dans la noticeUniversité ou école supérieure
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Nara Institute of Science and Technology Division of Biological Science pays non établi dans la noticeUniversité ou école supérieure
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University of California pays non établi dans la noticeUniversité ou école supérieure
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Kumamoto University International Research Organization for Advanced Science and Technology pays non établi dans la noticeUniversité ou école supérieure
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College of Biological Sciences Department of Plant Biology pays non établi dans la noticeUniversité ou école supérieure
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Faculty of Advanced Science and Technology pays non établi dans la noticeUniversité ou école supérieure
Department of Cell and Developmental Biology — University of Michigan, Division of Biological Science — Nara Institute of Science and Technology et University of California, avec 3 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.