A polarity pathway for exocyst-dependent intracellular tube extension
Abstract
Lumen extension in intracellular tubes can occur when vesicles fuse with an invading apical membrane. Within the C. elegans excretory cell, which forms an intracellular tube, the exocyst vesicle-tethering complex is enriched at the lumenal membrane and is required for its outgrowth, suggesting that exocyst-targeted vesicles extend the lumen. Here, we identify a pathway that promotes intracellular tube extension by enriching the exocyst at the lumenal membrane. We show that PAR-6 and PKC-3/aPKC concentrate at the lumenal membrane and promote lumen extension. Using acute protein depletion, we find that PAR-6 is required for exocyst membrane recruitment, whereas PAR-3, which can recruit the exocyst in mammals, appears dispensable for exocyst localization and lumen extension. Finally, we show that CDC-42 and RhoGEF EXC-5/FGD regulate lumen extension by recruiting PAR-6 and PKC-3 to the lumenal membrane. Our findings reveal a pathway that connects CDC-42, PAR proteins, and the exocyst to extend intracellular tubes.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 2, 3, 5, 6, and 7.
Article and author information
Author details
Funding
American Cancer Society (PF-16-175-01-DDC)
- Joshua Abrams
National Institutes of Health (F32HL136038)
- Joshua Abrams
National Institutes of Health (R01GM098492)
- Jeremy Nance
National Institutes of Health (R35GM118081)
- Jeremy Nance
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Kang Shen, Howard Hughes Medical Institute, Stanford University, United States
Version history
- Received: December 1, 2020
- Accepted: March 8, 2021
- Accepted Manuscript published: March 9, 2021 (version 1)
- Version of Record published: April 4, 2021 (version 2)
- Version of Record updated: May 25, 2021 (version 3)
Copyright
© 2021, Abrams & Nance
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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