Publication Date:
2022-05-25
Description:
© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution 3.0 License. The definitive version was published in Journal of Cell Biology 193 (2011): 1065-1081, doi:10.1083/jcb.201012143.
Description:
The septins are conserved, GTP-binding proteins important for cytokinesis, membrane compartmentalization, and exocytosis. However, it is unknown how septins are arranged within higher-order structures in cells. To determine the organization of septins in live cells, we developed a polarized fluorescence microscopy system to monitor the orientation of GFP dipole moments with high spatial and temporal resolution. When GFP was fused to septins, the arrangement of GFP dipoles reflected the underlying septin organization. We demonstrated in a filamentous fungus, a budding yeast, and a mammalian epithelial cell line that septin proteins were organized in an identical highly ordered fashion. Fluorescence anisotropy measurements indicated that septin filaments organized into pairs within live cells, just as has been observed in vitro. Additional support for the formation of pairs came from the observation of paired filaments at the cortex of cells using electron microscopy. Furthermore, we found that highly ordered septin structures exchanged subunits and rapidly rearranged. We conclude that septins assemble into dynamic, paired filaments in vivo and that this organization is conserved from yeast to mammals.
Description:
This work was supported by the National Science Foundation under
grant No. MCB-0719126 to A.S. Gladfelter, the National Institute of Biomedical
Imaging and Bioengineering under grant No. EB002583 to R. Oldenbourg,
a Drexel CURE grant from the State of Pennsylvania Tobacco Settlement Fund,
and National Institute of Neurological Disorders and Stroke grant NS48090-
06A to E.T. Spiliotis.
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
Permalink
