Handling Editor: Tamotsu Yoshimori
ABSTRACT
Lysosomes are compartments for the degradation of both endocytic and autophagic cargoes. The shape of lysosomes changes with cellular degradative demands; however, there is limited knowledge about the mechanisms or significance that underlies distinct lysosomal morphologies. Here, we found an extensive tubular autolysosomal network in Drosophila abdominal muscle remodeling during metamorphosis. The tubular network transiently appeared and exhibited the capacity to degrade autophagic cargoes. The tubular autolysosomal network was uniquely marked by the autophagic SNARE protein Syntaxin17 and its formation depended on both autophagic flux and degradative function, with the exception of the Atg12 and Atg8 ubiquitin-like conjugation systems. Among ATG-deficient mutants, the efficiency of lysosomal tubulation correlated with the phenotypic severity in muscle remodeling. The lumen of the tubular network was continuous and homogeneous across a broad region of the remodeling muscle. Altogether, we revealed that the dynamic expansion of a tubular autolysosomal network synchronizes the abundant degradative activity required for developmentally regulated muscle remodeling.
Footnotes
Competing interests
The authors declare no competing or financial interests.
Author contributions
Conceptualization: N.F.; Methodology: T.M., N.F.; Software: T.M., N.F.; Validation: T.M., N.F.; Formal analysis: T.M., N.F.; Investigation: T.M., Y.S., N.F.; Resources: T.M., A.A.K., M.F., N.F.; Data curation: N.F.; Writing - original draft: N.F.; Writing - review & editing: T.M., A.A.K., M.F., N.F.; Supervision: N.F.; Funding acquisition: A.A.K., M.F., N.F.
Funding
This work was supported in part by a Grant-in-Aid for Scientific Research (C) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT; grant number 18K06202 to N.F.), a Grant-in-Aid for Scientific Research (B) from MEXT (grant number 19H03220 to M.F.), a Grant-in-Aid for Scientific Research on Innovative Areas from MEXT (grant number 20H05315 to N.F.), Japan Science and Technology Agency (JST) PRESTO (grant number JPMJPR18H8 to N.F.), JST CREST (grant number JPMJCR17H4 to M.F.), a research grant from the Astellas Foundation for Research on Metabolic Disorders (N.F.), and the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award R01AR073840 (A.A.K.). Deposited in PMC for release after 12 months.
Supplementary information
Supplementary information available online at https://jcs.biologists.org/lookup/doi/10.1242/jcs.248336.supplemental
- Received April 30, 2020.
- Accepted October 1, 2020.
- © 2020. Published by The Company of Biologists Ltd
Log in using your username and password
Log in through your institution
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$30.00 .
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.