Augmin-dependent microtubule nucleation at microtubule walls in the spindle
McIntosh, J. Richard
MetadataShow full item record
The formation of a functional spindle requires microtubule (MT) nucleation from within the spindle, which depends on augmin. How augmin contributes to MT formation and organization is not known because augmin-dependent MTs have never been specifically visualized. In this paper, we identify augmin-dependent MTs and their connections to other MTs by electron tomography and 3D modeling. In metaphase spindles of human cells, the minus ends of MTs were located both around the centriole and in the body of the spindle. When augmin was knocked down, the latter population of MTs was significantly reduced. In control cells, we identified connections between the wall of one MT and the minus end of a neighboring MT. Interestingly, the connected MTs were nearly parallel, unlike other examples of end–wall connections between cytoskeletal polymers. Our observations support the concept of augmin-dependent MT nucleation at the walls of existing spindle MTs. Furthermore, they suggest a mechanism for maintaining polarized MT organization, even when noncentrosomal MT initiation is widespread.
© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Cell Biology 202 (2013): 25-33, doi:10.1083/jcb.201304031.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-ShareAlike 3.0 Unported
Showing items related by title, author, creator and subject.
The amyloid precursor protein of Alzheimer’s disease clusters at the organelle/microtubule interface on organelles that bind microtubules in an ATP dependent manner Stevenson, James W.; Conaty, Eliza A.; Walsh, Rylie B.; Poidomani, Paul J.; Samoriski, Colin M.; Scollins, Brianne J.; DeGiorgis, Joseph A. (Public Library of Science, 2016-01-27)The amyloid precursor protein (APP) is a causal agent in the pathogenesis of Alzheimer’s disease and is a transmembrane protein that associates with membrane-limited organelles. APP has been shown to co-purify through ...
Moriwaki, Takashi; Goshima, Gohta (Rockefeller University Press, 2016-10-31)Cytoplasmic microtubules (MTs) undergo growth, shrinkage, and pausing. However, how MT polymerization cycles are produced and spatiotemporally regulated at a molecular level is unclear, as the entire cycle has not been ...
Dynamics of myosin, microtubules, and Kinesin-6 at the cortex during cytokinesis in Drosophila S2 cells Vale, Ronald D.; Spudich, James A.; Griffis, Eric R. (Rockefeller University Press, 2009-08)Signals from the mitotic spindle during anaphase specify the location of the actomyosin contractile ring during cytokinesis, but the detailed mechanism remains unresolved. Here, we have imaged the dynamics of green fluorescent ...