Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Full Text Full Text (PDF, 2622K) PPT slides of all figures Supplemental Material Index Alert me when this article is cited Citation Map Services Email this article Similar articles in this journal Similar articles in PubMed Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Goshima, G. Articles by Vale, R. D. Search for Related Content PubMed PubMed Citation Articles by Goshima, G. Articles by Vale, R. D. Pubmed/NCBI databases Gene GEO Profiles HomoloGene Protein UniGene Substance via MeSH Social Bookmarking                            What's this?

Augmin: a protein complex required for centrosome-independent microtubule generation within the spindle

¹ Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
² Physiology Course 2007, Marine Biological Laboratory, Woods Hole, MA 02543
³ Max Planck Institute for Molecular Cell Biology and Genetics Dresden, 01307 Dresden, Germany
⁴ The Howard Hughes Medical Institute and the Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158

Correspondence to Gohta Goshima: goshima{at}iar.nagoya-u.ac.jp

Since the discovery of -tubulin, attention has focused on its involvement as a microtubule nucleator at the centrosome. However, mislocalization of -tubulin away from the centrosome does not inhibit mitotic spindle formation in Drosophila melanogaster, suggesting that a critical function for -tubulin might reside elsewhere. A previous RNA interference (RNAi) screen identified five genes (Dgt2–6) required for localizing -tubulin to spindle microtubules. We show that the Dgt proteins interact, forming a stable complex. We find that spindle microtubule generation is substantially reduced after knockdown of each Dgt protein by RNAi. Thus, the Dgt complex that we name "augmin" functions to increase microtubule number. Reduced spindle microtubule generation after augmin RNAi, particularly in the absence of functional centrosomes, has dramatic consequences on mitotic spindle formation and function, leading to reduced kinetochore fiber formation, chromosome misalignment, and spindle bipolarity defects. We also identify a functional human homologue of Dgt6. Our results suggest that an important mitotic function for -tubulin may lie within the spindle, where augmin and -tubulin function cooperatively to amplify the number of microtubules.

Abbreviations used in this paper: -TuRC, -tubulin ring complex; -TuSC, -tubulin small complex; kMT, kinetochore MT; MT, microtubule; NEBD, nuclear envelope breakdown.

© 2008 Goshima et al. This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.jcb.org/misc/terms.shtml). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

• Wu, G., Wei, R., Cheng, E., Ngo, B., Lee, W.-H. (2009). Hec1 Contributes to Mitotic Centrosomal Microtubule Growth for Proper Spindle Assembly through Interaction with Hice1. Mol. Biol. Cell 20: 4686-4695 [Abstract] [Full Text]  
• Bouissou, A., Verollet, C., Sousa, A., Sampaio, P., Wright, M., Sunkel, C. E., Merdes, A., Raynaud-Messina, B. (2009). {gamma}-Tubulin ring complexes regulate microtubule plus end dynamics. JCB 187: 327-334 [Abstract] [Full Text]  
• Paul, R., Wollman, R., Silkworth, W. T., Nardi, I. K., Cimini, D., Mogilner, A. (2009). Computer simulations predict that chromosome movements and rotations accelerate mitotic spindle assembly without compromising accuracy. Proc. Natl. Acad. Sci. USA 106: 15708-15713 [Abstract] [Full Text]  
• Vale, R. D., Spudich, J. A., Griffis, E. R. (2009). Dynamics of myosin, microtubules, and Kinesin-6 at the cortex during cytokinesis in Drosophila S2 cells. JCB 186: 727-738 [Abstract] [Full Text]  
• Wainman, A., Buster, D. W., Duncan, T., Metz, J., Ma, A., Sharp, D., Wakefield, J. G. (2009). A new Augmin subunit, Msd1, demonstrates the importance of mitotic spindle-templated microtubule nucleation in the absence of functioning centrosomes. Genes Dev. 23: 1876-1881 [Abstract] [Full Text]  
• Zhu, H., Fang, K., Fang, G. (2009). FAM29A, a target of Plk1 regulation, controls the partitioning of NEDD1 between the mitotic spindle and the centrosomes. J. Cell Sci. 122: 2750-2759 [Abstract] [Full Text]  
• Moutinho-Pereira, S., Debec, A., Maiato, H. (2009). Microtubule Cytoskeleton Remodeling by Acentriolar Microtubule-organizing Centers at the Entry and Exit from Mitosis in Drosophila Somatic Cells. Mol. Biol. Cell 20: 2796-2808 [Abstract] [Full Text]  
• Uehara, R., Nozawa, R.-s., Tomioka, A., Petry, S., Vale, R. D., Obuse, C., Goshima, G. (2009). The augmin complex plays a critical role in spindle microtubule generation for mitotic progression and cytokinesis in human cells. Proc. Natl. Acad. Sci. USA 106: 6998-7003 [Abstract] [Full Text]  
• Meireles, A. M., Fisher, K. H., Colombie, N., Wakefield, J. G., Ohkura, H. (2009). Wac: a new Augmin subunit required for chromosome alignment but not for acentrosomal microtubule assembly in female meiosis. JCB 184: 777-784 [Abstract] [Full Text]  
• Zhu, H., Coppinger, J. A., Jang, C.-Y., Yates, J. R. III, Fang, G. (2008). FAM29A promotes microtubule amplification via recruitment of the NEDD1-{gamma}-tubulin complex to the mitotic spindle. JCB 183: 835-848 [Abstract] [Full Text]  

Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents