Compartmentalized Toxoplasma EB1 bundles spindle microtubules to secure accurate chromosome segregation
| Autor: | Patrick T. Ebbert, Belinda U. Nwagbara, Chun-Ti Chen, Megan Kelly, Jessica Cruz de Leon, Laura Anne Lowery, Marc-Jan Gubbels, Naomi S. Morrissette, David J. P. Ferguson |
|---|---|
| Přispěvatelé: | Bloom, Kerry S |
| Rok vydání: | 2015 |
| Předmět: |
Protozoan Proteins
Mitosis Centrosome cycle Spindle Apparatus Biology Microtubules Medical and Health Sciences Spindle pole body Vaccine Related Xenopus laevis Chromosome Segregation parasitic diseases Genetics Animals Kinetochores Molecular Biology Centrosome Kinetochore Cell Cycle Articles Cell Biology Biological Sciences 3. Good health Spindle apparatus Cell biology Cell Compartmentation Spindle checkpoint Emerging Infectious Diseases Astral microtubules Multipolar spindles Toxoplasma Microtubule-Associated Proteins Developmental Biology |
| Zdroj: | Molecular biology of the cell, vol 26, iss 25 Chen, CT; Kelly, M; De Leon, J; Nwagbara, B; Ebbert, P; Ferguson, DJP; et al.(2015). Compartmentalized Toxoplasma EB1 bundles spindle microtubules to secure accurate chromosome segregation. Molecular Biology of the Cell, 26(25), 4562-4576. doi: 10.1091/mbc.E15-06-0437. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/9gm5k9tx Molecular Biology of the Cell |
| DOI: | 10.1091/mbc.E15-06-0437. |
| Popis: | The opportunistic apicomplexan parasite Toxoplasma gondii divides by intertwined closed mitosis and internal budding. Centrosome positioning and MT acetylation control spindle dynamics, and the MT-associated protein TgEB1 residing in the nucleus contributes to mitotic fidelity by bundling the spindle MTs. Toxoplasma gondii replicates asexually by a unique internal budding process characterized by interwoven closed mitosis and cytokinesis. Although it is known that the centrosome coordinates these processes, the spatiotemporal organization of mitosis remains poorly defined. Here we demonstrate that centrosome positioning around the nucleus may signal spindle assembly: spindle microtubules (MTs) are first assembled when the centrosome moves to the basal side and become extensively acetylated after the duplicated centrosomes reposition to the apical side. We also tracked the spindle MTs using the MT plus end–binding protein TgEB1. Endowed by a C-terminal NLS, TgEB1 resides in the nucleoplasm in interphase and associates with the spindle MTs during mitosis. TgEB1 also associates with the subpellicular MTs at the growing end of daughter buds toward the completion of karyokinesis. Depletion of TgEB1 results in escalated disintegration of kinetochore clustering. Furthermore, we show that TgEB1’s MT association in Toxoplasma and in a heterologous system (Xenopus) is based on the same principles. Finally, overexpression of a high-MT-affinity TgEB1 mutant promotes the formation of overstabilized MT bundles, resulting in avulsion of otherwise tightly clustered kinetochores. Overall we conclude that centrosome position controls spindle activity and that TgEB1 is critical for mitotic integrity. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|