Reticulon proteins modulate autophagy of the endoplasmic reticulum in maize endosperm
- University of Wisconsin-Madison, United States
- Washington University in St Louis, United States
Abstract
Reticulon (Rtn) proteins shape tubular domains of the endoplasmic reticulum (ER), and in some cases are autophagy receptors for selective ER turnover. We have found that maize Rtn1 and Rtn2 control ER homeostasis and autophagic flux in endosperm aleurone cells, where the ER accumulates lipid droplets and synthesizes storage protein accretions metabolized during germination. Maize Rtn1 and Rtn2 are expressed in the endosperm, localize to the ER, and re-model ER architecture in a dose-dependent manner. Rtn1 and Rtn2 interact with Atg8a using four Atg8-interacting motifs (AIMs) located at the C-terminus, cytoplasmic loop, and within the transmembrane segments. Binding between Rtn2 and Atg8 is elevated upon ER stress. Maize rtn2 mutants display increased autophagy and up-regulation of an ER stress-responsive chaperone. We propose that maize Rtn1 and Rtn2 act as receptors for autophagy-mediated ER turnover, and thus are critical for ER homeostasis and suppression of ER stress.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files.
Article and author information
Author details
Richard Scott Marshall
Richard David Vierstra
Funding
National Science Foundation (IOS-1840687)
- Marisa Otegui
Agriculture Hatch Act Formula Fund (WIS01791)
- Marisa Otegui
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Zhang 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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Reticulon proteins modulate autophagy of the endoplasmic reticulum in maize endosperm
eLife 9:e51918.
https://doi.org/10.7554/eLife.51918
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