Conserved Atg8 recognition sites mediate Atg4 association with autophagosomal membranes and Atg8 deconjugation.
Deconjugation of the Atg8/LC3 protein family members from phosphatidylethanolamine (PE) by Atg4 proteases is essential for autophagy progression, but how this event is regulated remains to be understood. Here, we show that yeast Atg4 is recruited onto autophagosomal membranes by direct binding to Atg8 via two evolutionarily conserved Atg8 recognition sites, a classical LC3-interacting region (LIR) at the C-terminus of the protein and a novel motif at the N-terminus. Although both sites are important for Atg4-Atg8 interactionin vivo, only the new N-terminal motif, close to the catalytic center, plays a key role in Atg4 recruitment to autophagosomal membranes and specific Atg8 deconjugation. We thus propose a model where Atg4 activity on autophagosomal membranes depends on the cooperative action of at least two sites within Atg4, in which one functions as a constitutive Atg8 binding module, while the other has a preference toward PE-bound Atg8.
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Susana
0000-0002-3146-5762
S
Abreu
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Franziska
F
Kriegenburg
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Rubén
0000-0002-8274-3259
R
Gómez-Sánchez
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Muriel
M
Mari
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Jana
J
Sánchez-Wandelmer
Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway.
Mads
M
Skytte Rasmussen
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Rodrigo
R
Soares Guimarães
Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories (MFPL), Vienna Biocenter (VBC), University of Vienna, Vienna, Austria.
Bettina
B
Zens
Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories (MFPL), Vienna Biocenter (VBC), University of Vienna, Vienna, Austria.
Martina
M
Schuschnig
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Ralph
R
Hardenberg
Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland.
Matthias
M
Peter
Molecular Cancer Research Group, Institute of Medical Biology, University of Tromsø - The Arctic University of Norway, Tromsø, Norway.
Terje
0000-0003-1451-9578
T
Johansen
Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories (MFPL), Vienna Biocenter (VBC), University of Vienna, Vienna, Austria.
Claudine
0000-0002-3324-4701
C
Kraft
Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories (MFPL), Vienna Biocenter (VBC), University of Vienna, Vienna, Austria.
Sascha
0000-0003-3786-8199
S
Martens
Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands f.m.reggiori@umcg.nl.|Department of Cell Biology, University Medical Center Utrecht, Utrecht, The Netherlands.
Fulvio
0000-0003-2652-2686
F
Reggiori
D000071182:Autophagosomes / Q000378:metabolism*; D001343:Autophagy; D000071190:Autophagy-Related Protein 8 Family / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000071183:Autophagy-Related Proteins / Q000235:genetics / Q000378:metabolism*; D008566:Membranes / Q000737:chemistry / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D010588:Phagosomes / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
C113757:ATG8 protein, S cerevisiae; C113755:Atg4 protein, S cerevisiae; D000071190:Autophagy-Related Protein 8 Family; D000071183:Autophagy-Related Proteins; D008869:Microtubule-Associated Proteins; D010714:Phosphatidylethanolamines; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; C483858:phosphatidylethanolamine
LC3; autophagosome; autophagy; deconjugation; phagophore assembly site