Abstract
Non-centrosomal microtubule organizing centers (MTOCs) are important for microtubule organization in many cell types. In fission yeast Schizosaccharomyces pombe, the protein Mto1, together with partner protein Mto2 (Mto1/2 complex), recruits the g-tubulin complex to multiple non-centrosomal MTOCs, including the nuclear envelope (NE). Here, we develop a comparative-interactome mass spectrometry approach to determine how Mto1 localizes to the NE. Surprisingly, we find that Mto1, a constitutively cytoplasmic protein, docks at nuclear pore complexes (NPCs), via interaction with exportin Crm1 and cytoplasmic FG-nucleoporin Nup146. Although Mto1 is not a nuclear export cargo, it binds Crm1 via a nuclear export signal-like sequence, and docking requires both Ran in the GTP-bound state and Nup146 FG repeats. In addition to determining the mechanism of MTOC formation at the NE, our results reveal a novel role for Crm1 and the nuclear export machinery in the stable docking of a cytoplasmic protein complex at NPCs.
Article and author information
Author details
Funding
Wellcome (94517)
- Xun X Bao
- Eric M Lynch
- Kenneth E Sawin
Japan Society for the Promotion of Science (JP25116006)
- Tomoko Kojidani
- Tokuko Haraguchi
The Darwin Trust of Edinburgh
- Xun X Bao
Wellcome (108504)
- Christos Spanos
- Juri Rappsilber
Wellcome (91020)
- Christos Spanos
- Juri Rappsilber
Wellcome (203149)
- Xun X Bao
- Christos Spanos
- Eric M Lynch
- Juri Rappsilber
- Kenneth E Sawin
Japan Society for the Promotion of Science (JP17H03636)
- Tomoko Kojidani
- Tokuko Haraguchi
Japan Society for the Promotion of Science (JP17H01444)
- Yasushi Hiraoka
Japan Society for the Promotion of Science (JP16H01309)
- Yasushi Hiraoka
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Karsten Weis, ETH Zurich, Switzerland
Publication history
- Received: November 9, 2017
- Accepted: May 21, 2018
- Accepted Manuscript published: May 29, 2018 (version 1)
- Version of Record published: June 19, 2018 (version 2)
Copyright
© 2018, Bao et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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