TY - JOUR
T1 - An N-terminal conserved region in human Atg3 couples membrane curvature sensitivity to conjugase activity during autophagy
AU - Ye, Yansheng
AU - Tyndall, Erin R.
AU - Bui, Van
AU - Tang, Zhenyuan
AU - Shen, Yan
AU - Jiang, Xuejun
AU - Flanagan, John M.
AU - Wang, Hong Gang
AU - Tian, Fang
N1 - Funding Information:
We gratefully acknowledge the lab of Dr. Sascha Martens for providing the yeast expression vector for Atg3, Atg7, and Atg8. We thank Dr. Christie McCracken for helping with mouse Atg7 preparation, Dr. Maria Bewley and Dr. Charles R. Sanders for helping with nanodisc and bicelle preparations, Dr. Thomas Spratt for discussions, and Dr. Ad Bax for his support with POMONA modeling. We are thankful for financial support from the National Institutes of Health NIGMS (5R01GM105963, 1R01GM127730, 1R01GM127954, R01 CA166413, and R01 GM113013) and the Four Diamonds Fund.
Publisher Copyright:
© 2021, The Author(s).
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/12
Y1 - 2021/12
N2 - During autophagy the enzyme Atg3 catalyzes the covalent conjugation of LC3 to the amino group of phosphatidylethanolamine (PE) lipids, which is one of the key steps in autophagosome formation. Here, we have demonstrated that an N-terminal conserved region of human Atg3 (hAtg3) communicates information from the N-terminal membrane curvature-sensitive amphipathic helix (AH), which presumably targets the enzyme to the tip of phagophore, to the C-terminally located catalytic core for LC3–PE conjugation. Mutations in the putative communication region greatly reduce or abolish the ability of hAtg3 to catalyze this conjugation in vitro and in vivo, and alter the membrane-bound conformation of the wild-type protein, as reported by NMR. Collectively, our results demonstrate that the N-terminal conserved region of hAtg3 works in concert with its geometry-selective AH to promote LC3–PE conjugation only on the target membrane, and substantiate the concept that highly curved membranes drive spatial regulation of the autophagosome biogenesis during autophagy.
AB - During autophagy the enzyme Atg3 catalyzes the covalent conjugation of LC3 to the amino group of phosphatidylethanolamine (PE) lipids, which is one of the key steps in autophagosome formation. Here, we have demonstrated that an N-terminal conserved region of human Atg3 (hAtg3) communicates information from the N-terminal membrane curvature-sensitive amphipathic helix (AH), which presumably targets the enzyme to the tip of phagophore, to the C-terminally located catalytic core for LC3–PE conjugation. Mutations in the putative communication region greatly reduce or abolish the ability of hAtg3 to catalyze this conjugation in vitro and in vivo, and alter the membrane-bound conformation of the wild-type protein, as reported by NMR. Collectively, our results demonstrate that the N-terminal conserved region of hAtg3 works in concert with its geometry-selective AH to promote LC3–PE conjugation only on the target membrane, and substantiate the concept that highly curved membranes drive spatial regulation of the autophagosome biogenesis during autophagy.
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U2 - 10.1038/s41467-020-20607-0
DO - 10.1038/s41467-020-20607-0
M3 - Article
C2 - 33446636
AN - SCOPUS:85099438923
VL - 12
JO - Nature Communications
JF - Nature Communications
SN - 2041-1723
IS - 1
M1 - 374
ER -