Cargando…

ATG9 vesicles comprise the seed membrane of mammalian autophagosomes

As the autophagosome forms, its membrane surface area expands rapidly, while its volume is kept low. Protein-mediated transfer of lipids from another organelle to the autophagosome likely drives this expansion, but as these lipids are only introduced into the cytoplasmic-facing leaflet of the organe...

Descripción completa

Detalles Bibliográficos
Autores principales: Olivas, Taryn J., Wu, Yumei, Yu, Shenliang, Luan, Lin, Choi, Peter, Guinn, Emily D., Nag, Shanta, De Camilli, Pietro V., Gupta, Kallol, Melia, Thomas J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Rockefeller University Press 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10148236/
https://www.ncbi.nlm.nih.gov/pubmed/37115958
http://dx.doi.org/10.1083/jcb.202208088
_version_ 1785034956376899584
author Olivas, Taryn J.
Wu, Yumei
Yu, Shenliang
Luan, Lin
Choi, Peter
Guinn, Emily D.
Nag, Shanta
De Camilli, Pietro V.
Gupta, Kallol
Melia, Thomas J.
author_facet Olivas, Taryn J.
Wu, Yumei
Yu, Shenliang
Luan, Lin
Choi, Peter
Guinn, Emily D.
Nag, Shanta
De Camilli, Pietro V.
Gupta, Kallol
Melia, Thomas J.
author_sort Olivas, Taryn J.
collection PubMed
description As the autophagosome forms, its membrane surface area expands rapidly, while its volume is kept low. Protein-mediated transfer of lipids from another organelle to the autophagosome likely drives this expansion, but as these lipids are only introduced into the cytoplasmic-facing leaflet of the organelle, full membrane growth also requires lipid scramblase activity. ATG9 harbors scramblase activity and is essential to autophagosome formation; however, whether ATG9 is integrated into mammalian autophagosomes remains unclear. Here we show that in the absence of lipid transport, ATG9 vesicles are already competent to collect proteins found on mature autophagosomes, including LC3-II. Further, we use styrene–maleic acid lipid particles to reveal the nanoscale organization of protein on LC3-II membranes; ATG9 and LC3-II are each fully integrated into expanding autophagosomes. The ratios of these two proteins at different stages of maturation demonstrate that ATG9 proteins are not continuously integrated, but rather are present on the seed vesicles only and become diluted in the expanding autophagosome membrane.
format Online
Article
Text
id pubmed-10148236
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-101482362023-10-28 ATG9 vesicles comprise the seed membrane of mammalian autophagosomes Olivas, Taryn J. Wu, Yumei Yu, Shenliang Luan, Lin Choi, Peter Guinn, Emily D. Nag, Shanta De Camilli, Pietro V. Gupta, Kallol Melia, Thomas J. J Cell Biol Article As the autophagosome forms, its membrane surface area expands rapidly, while its volume is kept low. Protein-mediated transfer of lipids from another organelle to the autophagosome likely drives this expansion, but as these lipids are only introduced into the cytoplasmic-facing leaflet of the organelle, full membrane growth also requires lipid scramblase activity. ATG9 harbors scramblase activity and is essential to autophagosome formation; however, whether ATG9 is integrated into mammalian autophagosomes remains unclear. Here we show that in the absence of lipid transport, ATG9 vesicles are already competent to collect proteins found on mature autophagosomes, including LC3-II. Further, we use styrene–maleic acid lipid particles to reveal the nanoscale organization of protein on LC3-II membranes; ATG9 and LC3-II are each fully integrated into expanding autophagosomes. The ratios of these two proteins at different stages of maturation demonstrate that ATG9 proteins are not continuously integrated, but rather are present on the seed vesicles only and become diluted in the expanding autophagosome membrane. Rockefeller University Press 2023-04-28 /pmc/articles/PMC10148236/ /pubmed/37115958 http://dx.doi.org/10.1083/jcb.202208088 Text en © 2023 Olivas et al. https://creativecommons.org/licenses/by-nc-sa/4.0/http://www.rupress.org/terms/This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Olivas, Taryn J.
Wu, Yumei
Yu, Shenliang
Luan, Lin
Choi, Peter
Guinn, Emily D.
Nag, Shanta
De Camilli, Pietro V.
Gupta, Kallol
Melia, Thomas J.
ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title_full ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title_fullStr ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title_full_unstemmed ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title_short ATG9 vesicles comprise the seed membrane of mammalian autophagosomes
title_sort atg9 vesicles comprise the seed membrane of mammalian autophagosomes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10148236/
https://www.ncbi.nlm.nih.gov/pubmed/37115958
http://dx.doi.org/10.1083/jcb.202208088
work_keys_str_mv AT olivastarynj atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT wuyumei atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT yushenliang atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT luanlin atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT choipeter atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT guinnemilyd atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT nagshanta atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT decamillipietrov atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT guptakallol atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes
AT meliathomasj atg9vesiclescomprisetheseedmembraneofmammalianautophagosomes