Mechanism of Atg9 recruitment by Atg11 in the cytoplasm-to-vacuole targeting pathway

Author(s)
Nicolas Coudevylle, Bartlomiej Banas, Verena Baumann, Martina Schuschnig, Anna Zawadzka-Kazimierczuk, Wiktor Kozminski, Sascha Martens
Abstract

Autophagy is a lysosomal degradation pathway for the removal of damaged and superfluous cytoplasmic material. This is achieved by the sequestration of this cargo material within double-membrane vesicles termed autophagosomes. Autophagosome formation is mediated by the conserved autophagy machinery. In selective autophagy, this machinery including the transmembrane protein Atg9 is recruited to specific cargo material via cargo receptors and the Atg11/FIP200 scaffold protein. The molecular details of the interaction between Atg11 and Atg9 are unclear, and it is still unknown how the recruitment of Atg9 is regulated. Here we employ NMR spectroscopy of the N-terminal disordered domain of Atg9 (Atg9-NTD) to map its interaction with Atg11 revealing that it involves two short peptides both containing a PLF motif. We show that the Atg9-NTD binds to Atg11 with an affinity of about 1 μM and that both PLF motifs contribute to the interaction. Mutation of the PLF motifs abolishes the interaction of the Atg9-NTD with Atg11, reduces the recruitment of Atg9 to the precursor aminopeptidase 1 (prApe1) cargo, and blocks prApe1 transport into the vacuole by the selective autophagy-like cytoplasm-to-vacuole (Cvt) targeting pathway while not affecting bulk autophagy. Our results provide mechanistic insights into the interaction of the Atg11 scaffold with the Atg9 transmembrane protein in selective autophagy and suggest a model where only clustered Atg11 when bound to the prApe1 cargo is able to efficiently recruit Atg9 vesicles.

Organisation(s)
Department of Biochemistry and Cell Biology
External organisation(s)
University of Warsaw, Medizinische Universität Wien
Journal
Journal of Biological Chemistry
Volume
298
No. of pages
10
ISSN
0021-9258
DOI
https://doi.org/10.1016/j.jbc.2022.101573
Publication date
02-2022
Peer reviewed
Yes
Austrian Fields of Science 2012
106002 Biochemistry
ASJC Scopus subject areas
Molecular Biology, Biochemistry, Cell Biology
Portal url
https://ucris.univie.ac.at/portal/en/publications/mechanism-of-atg9-recruitment-by-atg11-in-the-cytoplasmtovacuole-targeting-pathway(b8ab8286-af53-4b39-8e16-de03e4e084a2).html