| Autor: |
Chunmei Chang, C Alexander Boecker, Erika L.F. Holzbaur, James H. Hurley, Xuefeng Ren, Andrea K. H. Stavoe, Lisa M Strong, Cosmo Z. Buffalo, Thomas G Flower |
| Rok vydání: |
2021 |
| Předmět: |
|
| DOI: |
10.1101/2021.05.14.444175 |
| Popis: |
Autophagy is a cellular process that degrades cytoplasmic cargo by engulfing it in a double membrane vesicle, known as the autophagosome, and delivering it to the lysosome. The ATG12–5-16L1 complex is responsible for conjugating members of the ubiquitin-like ATG8 protein family to phosphatidylethanolamine in the growing autophagosomal membrane, known as the phagophore. ATG12–5-16L1 is recruited to the phagophore by a subset of the phosphatidylinositol 3-phosphate-binding seven bladed β-propeller WIPI proteins. We determined the crystal structure of WIPI2d in complex with the WIPI2 interacting region (W2IR) of ATG16L1 comprising residues 207-230 at 1.85 Å resolution. The structure shows that the ATG16L1 W2IR adopts an alpha helical conformation and binds in an electropositive and hydrophobic groove between WIPI2 β-propeller blades 2 and 3. Mutation of residues at the interface reduces or blocks the recruitment of ATG12–5-16L1 and the conjugation of the ATG8 protein LC3B to synthetic membranes. Interface mutants show a decrease in starvation-induced autophagy. Comparisons across the four human WIPIs suggest that WIPI1 and 2 belong to a W2IR-binding subclass responsible for localizing ATG12–5-16L1 and driving ATG8 lipidation, whilst WIPI3 and 4 belong to a second W34IR-binding subclass responsible for localizing ATG2, and so directing lipid supply to the nascent phagophore. The structure provides a framework for understanding the regulatory node connecting two central events in autophagy initiation, the action of the autophagic PI 3-kinase complex on the one hand, and ATG8 lipidation on the other. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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