Multiple Functions of ATG8 Family Proteins in Plant Autophagy.

Fan Bu,Xu Guo,Wei Huang,Liang Chen,Mingkang Yang

doi:10.3389/fcell.2020.00466

Fan Bu, Xu Guo + Show 3 more

Open Access

https://doi.org/10.3389/fcell.2020.00466

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Abstract

Autophagy is a major degradation process of cytoplasmic components in eukaryotes, and executes both bulk and selective degradation of targeted cargos. A set of autophagy-related (ATG) proteins participate in various stages of the autophagic process. Among ATGs, ubiquitin-like protein ATG8 plays a central role in autophagy. The ATG8 protein is conjugated to the membrane lipid phosphatidylethanolamine in a ubiquitin-like conjugation reaction that is essential for autophagosome formation. In addition, ATG8 interacts with various adaptor/receptor proteins to recruit specific cargos for degradation by selective autophagy. The ATG8-interacting proteins usually contain the ATG8-interacting motif (AIM) or the ubiquitin-interacting motif (UIM) for ATG8 binding. Unlike a single ATG8 gene in yeast, multiple ATG8 orthologs have been identified in the plant kingdom. The large diversity within the ATG8 family may explain the various functions of selective autophagy in plants. Here, we discuss and summarize the current view of the structure and function of ATG8 proteins in plants.

Highlights

Intracellular protein quality-control is crucial for successful cell growth and development, which requires a proper balance between protein synthesis and degradation
ATG8 proteins interact with various adaptor/receptor proteins to recruit specific targeted cargos for degradation through selective autophagy
The identification of ATG8-interacting autophagy receptor proteins helps us to understand how autophagy substrates are selected for degradation

Summary

Introduction

Intracellular protein quality-control is crucial for successful cell growth and development, which requires a proper balance between protein synthesis and degradation. SH3P2 is recruited to the phagophore assembly site (PAS) by membrane associated ATG8 protein; ATG8 binds to phosphatidylinositol 3-phosphate (PI3P) and coordinates with the PI3K complex to facilitate autophagosome formation. ATG8 proteins play a crucial role in selective autophagy through their interaction with various AIM/UIMcontaining proteins (Marshall and Vierstra, 2018; Lei and Klionsky, 2019).

Results

Conclusion