Reticulon proteins modulate autophagy of the endoplasmic reticulum in maize endosperm.

Content Provider	Europe PMC
Author	Zhang, Xiaoguo Ding, Xinxin Marshall, Richard Scott Paez-Valencia, Julio Lacey, Patrick Vierstra, Richard David Otegui, Marisa S
Editor	Bergmann, Dominique C Hardtke, Christian S
Copyright Year	2020
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.
Journal	eLife
Volume Number	9
PubMed Central reference number	PMC7046470
PubMed reference number	32011236
e-ISSN	2050084X
DOI	10.7554/elife.51918
Language	English
Publisher	eLife Sciences Publications, Ltd
Publisher Date	2020-02-03
Access Restriction	Open
Rights License	This article is distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use and redistribution provided that the original author and source are credited. © 2020, Zhang et al
Subject Keyword	autophagy ER stress endosperm ER-phagy Maize
Content Type	Text
Resource Type	Article
Subject	Immunology and Microbiology Neuroscience Medicine Biochemistry, Genetics and Molecular Biology