Spatial variation of microtubule depolymerization in large asters
Spatial variation of microtubule depolymerization in large asters
Date
2021-04-19
Authors
Ishihara, Keisuke
Decker, Franziska
Caldas, Paulo
Pelletier, James F.
Loose, Martin
Brugués, Jan
Mitchison, Timothy J.
Decker, Franziska
Caldas, Paulo
Pelletier, James F.
Loose, Martin
Brugués, Jan
Mitchison, Timothy J.
Linked Authors
Person
Person
Person
Person
Person
Alternative Title
Citable URI
As Published
Date Created
Location
DOI
10.1091/mbc.e20-11-0723
Related Materials
Replaces
Replaced By
Keywords
Abstract
Microtubule plus-end depolymerization rate is a potentially important target of physiological regulation, but it has been challenging to measure, so its role in spatial organization is poorly understood. Here we apply a method for tracking plus ends based on time difference imaging to measure depolymerization rates in large interphase asters growing in Xenopus egg extract. We observed strong spatial regulation of depolymerization rates, which were higher in the aster interior compared with the periphery, and much less regulation of polymerization or catastrophe rates. We interpret these data in terms of a limiting component model, where aster growth results in lower levels of soluble tubulin and microtubule-associated proteins (MAPs) in the interior cytosol compared with that at the periphery. The steady-state polymer fraction of tubulin was ∼30%, so tubulin is not strongly depleted in the aster interior. We propose that the limiting component for microtubule assembly is a MAP that inhibits depolymerization, and that egg asters are tuned to low microtubule density.
Description
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ishihara, K., Decker, F., Caldas, P., Pelletier, J. F., Loose, M., Brugués, J., & Mitchison, T. J. Spatial variation of microtubule depolymerization in large asters. Molecular Biology of the Cell, 32(9), (2021): 869-879, https://doi.org/10.1091/mbc.e20-11-0723.
Embargo Date
Citation
Ishihara, K., Decker, F., Caldas, P., Pelletier, J. F., Loose, M., Brugués, J., & Mitchison, T. J. (2021). Spatial variation of microtubule depolymerization in large asters. Molecular Biology of the Cell, 32(9), 869-879.