Publication Date:
2022-05-26
Description:
© 2008 Goshima et al. This article is distributed under the terms of a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license). The definitive version was published in Journal of Cell Biology 181 (2008): 421-429, doi:10.1083/jcb.200711053.
Description:
Since the discovery of γ-tubulin, attention has focused on its involvement as a microtubule nucleator at the centrosome. However, mislocalization of {gamma}-tubulin away from the centrosome does not inhibit mitotic spindle formation in Drosophila melanogaster, suggesting that a critical function for γ-tubulin might reside elsewhere. A previous RNA interference (RNAi) screen identified five genes (Dgt2–6) required for localizing γ-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 γ-tubulin may lie within the spindle, where augmin and γ-tubulin function cooperatively to amplify the number of microtubules.
Description:
This work is supported by the Special Coordination Funds for Promoting
Science and Technology (MEXT, Japan), the Global COE Program “Advanced
Systems-Biology: Designing the Biological Function” (MEXT), and the Uehara
Memorial Foundation.
Repository Name:
Woods Hole Open Access Server
Type:
Article
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video/quicktime
Format:
application/pdf
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