Structural basis for ATG9A recruitment to the ULK1 complex in mitophagy initiation

Ren, Xuefeng; Nguyen, Thanh N.; Lam, Wai Kit; Buffalo, Cosmo Z.; Lazarou, Michael; Yokom, Adam L.; Hurley, James H.

doi:10.1101/2022.07.12.499634

Cited by 4 publications

(3 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…S2G). This interaction was lost when mutating the conserved residues P833 and P834 in ATG9 C , confirming a recent independent structural analysis (Ren et al, 2022) (Fig. 1E and Fig.…”

Section: Figuresupporting

confidence: 89%

Metamorphic proteins at the basis of human autophagy initiation and lipid transfer

Nguyen

Lugarini

David

et al. 2022

Preprint

View full text Add to dashboard Cite

Autophagy is a conserved intracellular degradation pathway that uses de novo double-membrane vesicle (autophagosome) formation to target a wide range of cytoplasmic material for lysosomal degradation. In multicellular organisms, autophagy initiation requires the timely assembly of a contact site between the ER and the nascent autophagosome. Here, we report the in vitro reconstitution of a full-length seven-subunit human autophagy initiation super-complex and found at its core ATG13-101 and transmembrane protein ATG9. Assembly of this core complex requires the rare ability of ATG13 and ATG101 to adopt topologically distinct folds. The slow spontaneous conversion between folds creates a rate-limiting step to regulate self-assembly of the super-complex. The interaction of the core complex with ATG2-WIPI4 enhances tethering of membrane vesicles and accelerates lipid transfer of ATG2 by both ATG9 and ATG13-101. Our work uncovers the molecular basis of the contact site and its assembly mechanisms imposed by the metamorphosis of ATG13-101 to regulate autophagosome biogenesis in space and time.

show abstract

“…S2G). This interaction was lost when mutating the conserved residues P833 and P834 in ATG9 C , confirming a recent independent structural analysis (Ren et al, 2022) (Fig. 1E and Fig.…”

Section: Figuresupporting

confidence: 89%

Metamorphic proteins at the basis of human autophagy initiation and lipid transfer

Nguyen

Lugarini

David

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…It would be interesting to investigate the role of the HORMA domain within ATG101, an ULK1/2 complex subunit that has been shown to dimerize with ATG13 (Qi et al, 2015; Suzuki et al, 2015). ATG101 could conceivably allow the simultaneous binding of the ULK1/2 complex to ATG9A and the PI3K complex to enhance autophagosome formation (Ren et al, 2022).…”

Section: Discussionmentioning

confidence: 99%

Unconventional Initiation of PINK1/Parkin Mitophagy by Optineurin

Nguyen

Sawa-Makarska

Khuu

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Cargo sequestration is a fundamental step of selective autophagy in which cells generate a double membrane structure termed an autophagosome on the surface of cargoes. NDP52, TAX1BP1 and p62 bind FIP200 which recruits the ULK1/2 complex to initiate autophagosome formation on cargoes. How OPTN initiates autophagosome formation during selective autophagy remains unknown despite its importance in neurodegeneration. Here, we uncover an unconventional path of PINK1/Parkin mitophagy initiation by OPTN that does not begin with FIP200 binding nor require the ULK1/2 kinases. Using gene-edited cell lines and in vitro reconstitutions, we show that OPTN utilizes the kinase TBK1 which binds directly to the class III phosphatidylinositol 3-kinase complex I to initiate mitophagy. During NDP52 mitophagy initiation, TBK1 is functionally redundant with ULK1/2, classifying TBK1’s role as a selective autophagy initiating kinase. Overall, this work reveals that OPTN mitophagy initiation is mechanistically distinct and highlights the mechanistic plasticity of selective autophagy pathways.

show abstract

“…Finally, ATG13 is 10-fold more abundant than ULK1 and given its ability to interact with PIP3 enriched membranes we postulate that ATG13 recruitment is one of the earliest events in autophagosome formation. In future work it will be critical to define the molecular mechanism by which the ULK1 complex and PI3kinase are directed to ATG9 vesicles to initiate autophagosome formation (Ren et al, 2022).…”

Section: The Ulk1 Complex and Pi3-kinase Form A Positive Feedback Loo...mentioning

confidence: 99%

Systematic Analysis of Autophagy Identifies Atg9 Vesicles as the Origin of the Phagophore

Broadbent

Barnaba

Schmidt

2022

Preprint

View full text Add to dashboard Cite

Autophagy is a catabolic pathway required for the clearance and recycling of cytoplasmic materials. Upregulation and dysfunction of autophagy contributes to the pathology of cancer and neurogenerative diseases, respectively. To define the molecular mechanisms that control autophagic flux it is critical to quantitatively characterize the dynamic behavior of autophagy factors in living cells. Using a panel of 9 cell lines expressing HaloTagged autophagy factors from their endogenous loci, we systematically analyze the abundance, single-molecule dynamics, and autophagosome association kinetics of a wide variety of autophagy proteins involved in the initiation and maturation of the autophagosome. Our results reveal that phagophores are initiated by the accumulation of autophagy factors on mobile ATG9 vesicles and tethering of these ATG9 vesicles to donor membranes by ATG2 is a key step in phagophore maturation. In addition, we demonstrate that the overall lifetime of an autophagosome is approximately 160 seconds and the majority of phagophore initiation events fail to produce mature autophagosomes. In total our work establishes a new experimental framework to quantitatively analyze autophagy and demonstrates that ATG9 vesicles are the seeds for autophagosome formation in human cells.

show abstract

Structural basis for ATG9A recruitment to the ULK1 complex in mitophagy initiation

Cited by 4 publications

References 62 publications

Metamorphic proteins at the basis of human autophagy initiation and lipid transfer

Metamorphic proteins at the basis of human autophagy initiation and lipid transfer

Unconventional Initiation of PINK1/Parkin Mitophagy by Optineurin

Systematic Analysis of Autophagy Identifies Atg9 Vesicles as the Origin of the Phagophore

Contact Info

Product

Resources

About