Abstract
Autophagosomes are formed by the enlargement and sealing of phagophores. This is accompanied by the recruitment and release of autophagy-related (Atg) proteins that function therein. Presently, the relationship among factors that act after the initial emergence of the phagophore is unclear. The endosomal sorting complexes required for transport (ESCRT) machinery and Atg4 are known to function in phagophore sealing and Atg8 release, respectively. Here we show that biochemically, both Atg4 and ESCRT promoted phagophore sealing. Intriguingly, Atg4-mediated release of Atg8 from the phagophore promoted phagophore sealing even in the absence of ESCRT. This sealing activity could be reconstituted in vitro using cell lysate and purified Atg4. To elucidate the temporal relationship between Atg4 and ESCRT, we charted a timeline of the autophagosome formation cycle based on the trafficking of Atg proteins and mapped the actions of Atg4 and ESCRT to specific stages. The temporal impact of Atg4-mediated release of Atg8 from phagophore was mapped to the stage after the assembly of phagophore assembly site (PAS) scaffold and phosphatidylinositol-3-kinase (PtdIns-3-K) complex; its retardation only extended the duration of Atg8 release stage, leading to delayed phagophore sealing and accumulation of multiple phagophores. The impacts of ESCRT were mapped to two stages. In addition to promoting phagophore sealing, it also dictates whether PtdIns-3-K recruitment can occur by controlling Atg9 trafficking, thereby determining the incidence of autophagosome formation. Accordingly, ESCRT deficiency led to a combination of reduced autophagosome frequency and extended autophagosome formation duration, manifesting as reduced autophagic flux but normal apparent Atg8 puncta number. Our study thus identifies Atg4-mediated Atg8 shedding as a novel membrane scission mechanism and reveals a new early-stage role for ESCRT in autophagy.
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References
Nishimura T, Tooze SA. Emerging roles of ATG proteins and membrane lipids in autophagosome formation. Cell Discov. 2020;6:32.
Nakatogawa H. Mechanisms governing autophagosome biogenesis. Nat Rev Mol Cell Biol. 2020;21:439–58.
Hollenstein DM, Kraft C. Autophagosomes are formed at a distinct cellular structure. Curr Opin Cell Biol. 2020;65:50–7.
Graef M, Friedman JR, Graham C, Babu M, Nunnari J. ER exit sites are physical and functional core autophagosome biogenesis components. Mol Biol Cell. 2013;24:2918–31.
Suzuki K, Akioka M, Kondo-Kakuta C, Yamamoto H, Ohsumi Y. Fine mapping of autophagy-related proteins during autophagosome formation in Saccharomyces cerevisiae. J Cell Sci. 2013;126:2534–44.
Hollenstein DM, Gomez-Sanchez R, Ciftci A, Kriegenburg F, Mari M, Torggler R, et al. Vac8 spatially confines autophagosome formation at the vacuole in S. cerevisiae. J Cell Sci. 2019;132:jcs235002.
Axe EL, Walker SA, Manifava M, Chandra P, Roderick HL, Habermann A, et al. Autophagosome formation from membrane compartments enriched in phosphatidylinositol 3-phosphate and dynamically connected to the endoplasmic reticulum. J Cell Biol. 2008;182:685–701.
Koyama-Honda I, Itakura E, Fujiwara TK, Mizushima N. Temporal analysis of recruitment of mammalian ATG proteins to the autophagosome formation site. Autophagy. 2013;9:1491–9.
Karanasios E, Stapleton E, Manifava M, Kaizuka T, Mizushima N, Walker SA, et al. Dynamic association of the ULK1 complex with omegasomes during autophagy induction. J Cell Sci. 2013;126:5224–38.
Broadbent DG, Barnaba C, Perez GI, Schmidt JC. Quantitative analysis of autophagy reveals the role of ATG9 and ATG2 in autophagosome formation. J Cell Biol. 2023;222:e202210078.
Nguyen TN, Lazarou M. A unifying model for the role of the ATG8 system in autophagy. J Cell Sci. 2022;135:jcs258997.
Noda NN. Atg2 and Atg9: Intermembrane and interleaflet lipid transporters driving autophagy. Biochim Biophys Acta Mol Cell Biol Lipids. 2021;1866:158956.
Cebollero E, van der Vaart A, Zhao M, Rieter E, Klionsky DJ, Helms JB, et al. Phosphatidylinositol-3-phosphate clearance plays a key role in autophagosome completion. Curr Biol. 2012;22:1545–53.
Yu ZQ, Ni T, Hong B, Wang HY, Jiang FJ, Zou S, et al. Dual roles of Atg8-PE deconjugation by Atg4 in autophagy. Autophagy. 2012;8:883–92.
Nakatogawa H, Ishii J, Asai E, Ohsumi Y. Atg4 recycles inappropriately lipidated Atg8 to promote autophagosome biogenesis. Autophagy. 2012;8:177–86.
Abreu S, Kriegenburg F, Gomez-Sanchez R, Mari M, Sanchez-Wandelmer J, Skytte Rasmussen M, et al. Conserved Atg8 recognition sites mediate Atg4 association with autophagosomal membranes and Atg8 deconjugation. EMBO Rep. 2017;18:765–80.
Kauffman KJ, Yu S, Jin J, Mugo B, Nguyen N, O’Brien A, et al. Delipidation of mammalian Atg8-family proteins by each of the four ATG4 proteases. Autophagy. 2018;14:992–1010.
Knorr RL, Lipowsky R, Dimova R. Autophagosome closure requires membrane scission. Autophagy. 2015;11:2134–7.
Takahashi Y, He H, Tang Z, Hattori T, Liu Y, Young MM, et al. An autophagy assay reveals the ESCRT-III component CHMP2A as a regulator of phagophore closure. Nat Commun. 2018;9:2855.
Zhou F, Wu Z, Zhao M, Murtazina R, Cai J, Zhang A, et al. Rab5-dependent autophagosome closure by ESCRT. J Cell Biol. 2019;218:1908–27.
Zhen Y, Spangenberg H, Munson MJ, Brech A, Schink KO, Tan KW, et al. ESCRT-mediated phagophore sealing during mitophagy. Autophagy. 2020;16:826–41.
Jin M, Klionsky DJ. Transcriptional regulation of ATG9 by the Pho23-Rpd3 complex modulates the frequency of autophagosome formation. Autophagy. 2014;10:1681–2.
Liu XM, Yamasaki A, Du XM, Coffman VC, Ohsumi Y, Nakatogawa H, et al. Lipidation-independent vacuolar functions of Atg8 rely on its noncanonical interaction with a vacuole membrane protein. Elife. 2018;7:e41237.
He CW, Cui XF, Ma SJ, Xu Q, Ran YP, Chen WZ, et al. Membrane recruitment of Atg8 by Hfl1 facilitates turnover of vacuolar membrane proteins in yeast cells approaching stationary phase. BMC Biol. 2021;19:117.
Backues SK, Chen D, Ruan J, Xie Z, Klionsky DJ. Estimating the size and number of autophagic bodies by electron microscopy. Autophagy. 2014;10:155–64.
Azuma T, Kei T. Super-resolution spinning-disk confocal microscopy using optical photon reassignment. Opt Express. 2015;23:15003–11.
Tang S, Henne WM, Borbat PP, Buchkovich NJ, Freed JH, Mao Y, et al. Structural basis for activation, assembly and membrane binding of ESCRT-III Snf7 filaments. Elife. 2015;4:e12548.
Zhu J, Deng S, Lu P, Bu W, Li T, Yu L, et al. The Ccl1-Kin28 kinase complex regulates autophagy under nitrogen starvation. J Cell Sci. 2016;129:135–44.
Klionsky DJ, Cueva R, Yaver DS. Aminopeptidase I of Saccharomyces cerevisiae is localized to the vacuole independent of the secretory pathway. J Cell Biol. 1992;119:287–99.
Darsow T, Rieder SE, Emr SD. A multispecificity syntaxin homologue, Vam3p, essential for autophagic and biosynthetic protein transport to the vacuole. J Cell Biol. 1997;138:517–29.
Yen WL, Klionsky DJ. Proteinase protection of prApe1 as a tool to monitor Cvt vesicle/autophagosome biogenesis. Autophagy. 2012;8:1245–9.
Kirisako T, Ichimura Y, Okada H, Kabeya Y, Mizushima N, Yoshimori T, et al. The reversible modification regulates the membrane-binding state of Apg8/Aut7 essential for autophagy and the cytoplasm to vacuole targeting pathway. J Cell Biol. 2000;151:263–76.
Li D, Song JZ, Shan MH, Li SP, Liu W, Li H, et al. A fluorescent tool set for yeast Atg proteins. Autophagy. 2015;11:954–60.
Steinfeld N, Lahiri V, Morrison A, Metur SP, Klionsky DJ, Weisman LS. Elevating PI3P drives select downstream membrane trafficking pathways. Mol Biol Cell. 2021;32:143–56.
Kageyama S, Omori H, Saitoh T, Sone T, Guan JL, Akira S, et al. The LC3 recruitment mechanism is separate from Atg9L1-dependent membrane formation in the autophagic response against Salmonella. Mol Biol Cell. 2011;22:2290–300.
Suzuki K, Kubota Y, Sekito T, Ohsumi Y. Hierarchy of Atg proteins in pre-autophagosomal structure organization. Genes Cells. 2007;12:209–18.
Reggiori F, Tucker KA, Stromhaug PE, Klionsky DJ. The Atg1-Atg13 complex regulates Atg9 and Atg23 retrieval transport from the pre-autophagosomal structure. Dev Cell. 2004;6:79–90.
Backues SK, Orban DP, Bernard A, Singh K, Cao Y, Klionsky DJ. Atg23 and Atg27 act at the early stages of Atg9 trafficking in S. cerevisiae. Traffic. 2015;16:172–90.
Suzuki K, Kirisako T, Kamada Y, Mizushima N, Noda T, Ohsumi Y. The pre-autophagosomal structure organized by concerted functions of APG genes is essential for autophagosome formation. EMBO J. 2001;20:5971–81.
Shintani T, Klionsky DJ. Cargo proteins facilitate the formation of transport vesicles in the cytoplasm to vacuole targeting pathway. J Biol Chem. 2004;279:29889–94.
Nair U, Yen WL, Mari M, Cao Y, Xie Z, Baba M, et al. A role for Atg8-PE deconjugation in autophagosome biogenesis. Autophagy. 2012;8:780–93.
Agrotis A, von Chamier L, Oliver H, Kiso K, Singh T, Ketteler R. Human ATG4 autophagy proteases counteract attachment of ubiquitin-like LC3/GABARAP proteins to other cellular proteins. J Biol Chem. 2019;294:12610–21.
Nguyen TN, Padman BS, Zellner S, Khuu G, Uoselis L, Lam WK, et al. ATG4 family proteins drive phagophore growth independently of the LC3/GABARAP lipidation system. Mol Cell. 2021;81:2013–30.e9.
Gatica D, Wen X, Cheong H, Klionsky DJ. Vac8 determines phagophore assembly site vacuolar localization during nitrogen starvation-induced autophagy. Autophagy. 2021;17:1636–48.
Hollenstein DM, Licheva M, Konradi N, Schweida D, Mancilla H, Mari M, et al. Spatial control of avidity regulates initiation and progression of selective autophagy. Nat Commun. 2021;12:7194.
Tamura N, Oku M, Sakai Y. Atg8 regulates vacuolar membrane dynamics in a lipidation-independent manner in Pichia pastoris. J Cell Sci. 2010;123:4107–16.
Wang CW, Miao YH, Chang YS. A sterol-enriched vacuolar microdomain mediates stationary phase lipophagy in budding yeast. J Cell Biol. 2014;206:357–66.
Nakatogawa H, Ichimura Y, Ohsumi Y. Atg8, a ubiquitin-like protein required for autophagosome formation, mediates membrane tethering and hemifusion. Cell. 2007;130:165–78.
Maruyama T, Alam JM, Fukuda T, Kageyama S, Kirisako H, Ishii Y, et al. Membrane perturbation by lipidated Atg8 underlies autophagosome biogenesis. Nat Struct Mol Biol. 2021;28:583–93.
Zhang W, Nishimura T, Gahlot D, Saito C, Davis C, Jefferies HBJ, et al. Autophagosome membrane expansion is mediated by the N-terminus and cis-membrane association of human ATG8s. Elife. 2023;12:e89185.
Manil-Segalen M, Lefebvre C, Culetto E, Legouis R. Need an ESCRT for autophagosomal maturation? Commun Integr Biol. 2012;5:566–71.
Kraft C, Reggiori F. Phagophore closure, autophagosome maturation and autophagosome fusion during macroautophagy in the yeast Saccharomyces cerevisiae. FEBS Lett. 2024;598:73–83.
Wang R, Miao G, Shen JL, Fortier TM, Baehrecke EH. ESCRT dysfunction compromises endoplasmic reticulum maturation and autophagosome biogenesis in Drosophila. Curr Biol. 2022;32:1262–74.e4.
Tsuboyama K, Koyama-Honda I, Sakamaki Y, Koike M, Morishita H, Mizushima N. The ATG conjugation systems are important for degradation of the inner autophagosomal membrane. Science. 2016;354:1036–41.
Lin MG, Schoneberg J, Davies CW, Ren X, Hurley JH. The dynamic Atg13-free conformation of the Atg1 EAT domain is required for phagophore expansion. Mol Biol Cell. 2018;29:1228–37.
Kraft C, Kijanska M, Kalie E, Siergiejuk E, Lee SS, Semplicio G, et al. Binding of the Atg1/ULK1 kinase to the ubiquitin-like protein Atg8 regulates autophagy. EMBO J. 2012;31:3691–703.
Nakatogawa H, Ohbayashi S, Sakoh-Nakatogawa M, Kakuta S, Suzuki SW, Kirisako H, et al. The autophagy-related protein kinase Atg1 interacts with the ubiquitin-like protein Atg8 via the Atg8 family interacting motif to facilitate autophagosome formation. J Biol Chem. 2012;287:28503–7.
Barz S, Kriegenburg F, Henning A, Bhattacharya A, Mancilla H, Sanchez-Martin P, et al. Atg1 kinase regulates autophagosome-vacuole fusion by controlling SNARE bundling. EMBO Rep. 2020;21:e51869.
Gao J, Kurre R, Rose J, Walter S, Frohlich F, Piehler J, et al. Function of the SNARE Ykt6 on autophagosomes requires the Dsl1 complex and the Atg1 kinase complex. EMBO Rep. 2020;21:e50733.
Schreiber A, Collins BC, Davis C, Enchev RI, Sedra A, D’Antuono R, et al. Multilayered regulation of autophagy by the Atg1 kinase orchestrates spatial and temporal control of autophagosome formation. Mol Cell. 2021;81:5066–81.e10.
Pengo N, Agrotis A, Prak K, Jones J, Ketteler R. A reversible phospho-switch mediated by ULK1 regulates the activity of autophagy protease ATG4B. Nat Commun. 2017;8:294.
Alemu EA, Lamark T, Torgersen KM, Birgisdottir AB, Larsen KB, Jain A, et al. ATG8 family proteins act as scaffolds for assembly of the ULK complex: sequence requirements for LC3-interacting region (LIR) motifs. J Biol Chem. 2012;287:39275–90.
Joachim J, Jefferies HB, Razi M, Frith D, Snijders AP, Chakravarty P, et al. Activation of ULK kinase and autophagy by GABARAP trafficking from the centrosome is regulated by WAC and GM130. Mol Cell. 2015;60:899–913.
Grunwald DS, Otto NM, Park JM, Song D, Kim DH. GABARAPs and LC3s have opposite roles in regulating ULK1 for autophagy induction. Autophagy. 2020;16:600–14.
Wang C, Wang H, Zhang D, Luo W, Liu R, Xu D, et al. Phosphorylation of ULK1 affects autophagosome fusion and links chaperone-mediated autophagy to macroautophagy. Nat Commun. 2018;9:3492.
Acknowledgements
The authors would like to thank Drs. Caiji Gao (South China Normal University, CN), Lv Hong (Fudan University, CN), Jia-Hong Lu (University of Macau, CN), Yoshinori Ohsumi (Tokyo Institute of Technology, JP), Christian Ungermann (University of Osnabrück, DE), Lois Weisman (University of Michigan, Ann Arbor, US), Cong Yi (Zhejiang University, CN), and Xin-Qing Zhao (Shanghai Jiao Tong University) for gifts of strains and reagents, thank Ms Ge Wang, Dr Jing Liu, and Dr Meng-Yu Yan (Instrumental Analysis Center, SJTU) for technical assistance in TEM.
Funding
This work was supported by National Natural Science Foundation of China (91754110, 32270796) and Shanghai Municipal Science and Technology Commission (22ZR1433800).
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Conceptualization: HL and ZX; Investigation: HL, JZS, CWH, MXX, ZTZ, YZ, XJL, and LC; Writing—Original Draft: HL and ZX; Project administration: JZ; Supervision: QG and ZX; Funding acquisition: ZX.
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Li, H., Song, JZ., He, CW. et al. Temporal dissection of the roles of Atg4 and ESCRT in autophagosome formation in yeast. Cell Death Differ 32, 866–879 (2025). https://doi.org/10.1038/s41418-024-01438-8
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DOI: https://doi.org/10.1038/s41418-024-01438-8
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