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Coordination of opposite-polarity microtubule motors

Many cargoes move bidirectionally, frequently reversing course between plus- and minus-end microtubule travel. For such cargoes, the extent and importance of interactions between the opposite-polarity motors is unknown. In this paper we test whether opposite-polarity motors on lipid droplets in Dros...

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Detalles Bibliográficos
Autores principales: Gross, Steven P., Welte, Michael A., Block, Steven M., Wieschaus, Eric F.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2002
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2174082/
https://www.ncbi.nlm.nih.gov/pubmed/11854311
http://dx.doi.org/10.1083/jcb.200109047
Descripción
Sumario:Many cargoes move bidirectionally, frequently reversing course between plus- and minus-end microtubule travel. For such cargoes, the extent and importance of interactions between the opposite-polarity motors is unknown. In this paper we test whether opposite-polarity motors on lipid droplets in Drosophila embryos are coordinated and avoid interfering with each other's activity, or whether they engage in a tug of war. To this end we impaired the minus-end transport machinery using dynein and dynactin mutations, and then investigated whether plus-end motion was improved or disrupted. We observe a surprisingly severe impairment of plus-end motion due to these alterations of minus-end motor activity. These observations are consistent with a coordination hypothesis, but cannot be easily explained with a tug of war model. Our measurements indicate that dynactin plays a crucial role in the coordination of plus- and minus-end–directed motors. Specifically, we propose that dynactin enables dynein to participate efficiently in bidirectional transport, increasing its ability to stay “on” during minus-end motion and keeping it “off” during plus-end motion.