Mammalian Spindle Orientation and Position Respond to Changes in Cell Shape in a Dynein-dependent Fashion
Overview
Molecular Biology
Authors
Affiliations
In animal cells, positioning of the mitotic spindle is crucial for defining the plane of cytokinesis and the size ratio of daughter cells. We have characterized this phenomenon in a rat epithelial cell line using microscopy, micromanipulation, and microinjection. Unmanipulated cells position the mitotic spindle near their geometric center, with the spindle axis lying roughly parallel to the long axis of the cell. Spindles that were initially misoriented underwent directed rotation and caused a delay in anaphase onset. To gain further insight into this process, we gently deformed cells with a blunted glass needle to change the spatial relationship between the cortex and spindle. This manipulation induced spindle movement or rotation in metaphase and/or anaphase, until the spindle reached a proper position relative to the deformed shape. Spindle positioning was inhibited by either treatment with low doses of nocodazole or microinjection of antibodies against dynein, apparently due to the disruption of the organization of dynein and/or astral microtubules. Our results suggest that mitotic cells continuously monitor and maintain the position of the spindle relative to the cortex. This process is likely driven by interactions among astral microtubules, the motor protein dynein, and the cell cortex and may constitute part of a mitotic checkpoint mechanism.
A cytokinetic ring-driven cell rotation achieves Hertwig's rule in early development.
Middelkoop T, Neipel J, Cornell C, Naumann R, Pimpale L, Julicher F Proc Natl Acad Sci U S A. 2024; 121(25):e2318838121.
PMID: 38870057 PMC: 11194556. DOI: 10.1073/pnas.2318838121.
Matsumura F, Murayama T, Kuriyama R, Matsumura A, Yamashiro S Cytoskeleton (Hoboken). 2024; 81(12):872-882.
PMID: 38700016 PMC: 11615836. DOI: 10.1002/cm.21871.
Stier A, Gilberto S, Mohamed W, Royall L, Helenius J, Mikicic I EMBO J. 2023; 42(17):e112847.
PMID: 37365982 PMC: 10476281. DOI: 10.15252/embj.2022112847.
Li X, Bloomfield M, Bridgeland A, Cimini D, Chen J Mol Biol Cell. 2023; 34(9):ar90.
PMID: 37342878 PMC: 10398891. DOI: 10.1091/mbc.E22-10-0485.
Cortical dynein drives centrosome clustering in cells with centrosome amplification.
Mercadante D, Aaron W, Olson S, Manning A Mol Biol Cell. 2023; 34(6):ar63.
PMID: 37017483 PMC: 10208098. DOI: 10.1091/mbc.E22-07-0296.