Campus Units

Biochemistry, Biophysics and Molecular Biology, Roy J. Carver Department of

Document Type

Article

Publication Version

Published Version

Publication Date

9-15-2012

Journal or Book Title

Molecular Biology of the Cell

Volume

23

Issue

18

First Page

3532

Last Page

3541

DOI

10.1091/mbc.e12-06-0429

Abstract

The concept of a spindle matrix has long been proposed. Whether such a structure exists, however, and what its molecular and structural composition are have remained controversial. In this study, using a live-imaging approach in Drosophilasyncytial embryos, we demonstrate that nuclear proteins reorganize during mitosis to form a highly dynamic, viscous spindle matrix that embeds the microtubule spindle apparatus, stretching from pole to pole. We show that this “internal” matrix is a distinct structure from the microtubule spindle and from a lamin B–containing spindle envelope. By injection of 2000-kDa dextran, we show that the disassembling nuclear envelope does not present a diffusion barrier. Furthermore, when microtubules are depolymerized with colchicine just before metaphase the spindle matrix contracts and coalesces around the chromosomes, suggesting that microtubules act as “struts” stretching the spindle matrix. In addition, we demonstrate that the spindle matrix protein Megator requires its coiled-coil amino-terminal domain for spindle matrix localization, suggesting that specific interactions between spindle matrix molecules are necessary for them to form a complex confined to the spindle region. The demonstration of an embedding spindle matrix lays the groundwork for a more complete understanding of microtubule dynamics and of the viscoelastic properties of the spindle during cell division.

Comments

This article is published as Yao, Changfu, Uttama Rath, Helder Maiato, David Sharp, Jack Girton, Kristen M. Johansen, and Jørgen Johansen. "A nuclear-derived proteinaceous matrix embeds the microtubule spindle apparatus during mitosis." Molecular biology of the cell23, no. 18 (2012): 3532-3541. doi: 10.1091/mbc.e12-06-0429.

Creative Commons License

Creative Commons Attribution-Noncommercial-Share Alike 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

Copyright Owner

Yao et al.

Language

en

File Format

application/pdf

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