PUBLICATION

The different roles of V-ATPase a subunits in phagocytosis/endocytosis and autophagy

Authors
Chen, Q., Kou, H., Demy, D.L., Liu, W., Li, J., Wen, Z., Herbomel, P., Huang, Z., Zhang, W., Xu, J.
ID
ZDB-PUB-240615-2
Date
2024
Source
Autophagy   20(10): 2297-2313 (Journal)
Registered Authors
Demy, Doris-Lou, Herbomel, Philippe, Huang, Zhibin, Liu, Wei, Xu, Jin, Zhang, Wenqing
Keywords
Autophagy, V-ATPase, microglia, phagosome maturation, zebrafish
MeSH Terms
  • Microglia/metabolism
  • Mutation/genetics
  • Autophagy*/physiology
  • Endocytosis*/physiology
  • Protein Subunits/metabolism
  • Lysosomes*/metabolism
  • Phagosomes*/metabolism
  • Vacuolar Proton-Translocating ATPases*/metabolism
  • Zebrafish*
  • Phagocytosis*/physiology
  • Animals
  • Mice
PubMed
38873931 Full text @ Autophagy
Abstract
Microglia are specialized macrophages responsible for the clearance of dead neurons and pathogens by phagocytosis and degradation. The degradation requires phagosome maturation and acidification provided by the vesicular- or vacuolar-type H+-translocating adenosine triphosphatase (V-ATPase), which is composed of the cytoplasmic V1 domain and the membrane-embedded Vo domain. The V-ATPase a subunit, an integral part of the Vo domain, has four isoforms in mammals. The functions of different isoforms on phagosome maturation in different cells/species remain controversial. Here we show that mutations of both the V-ATPase Atp6v0a1 and Tcirg1b/Atp6v0a3 subunits lead to the accumulation of phagosomes in zebrafish microglia. However, their mechanisms are different. The V-ATPase Atp6v0a1 subunit is mainly distributed in early and late phagosomes. Defects of this subunit lead to a defective transition from early phagosomes to late phagosomes. In contrast, The V-ATPase Tcirg1b/Atp6v0a3 subunit is primarily located on lysosomes and regulates late phagosome-lysosomal fusion. Defective Tcirg1b/Atp6v0a3, but not Atp6v0a1 subunit leads to reduced acidification and impaired macroautophagy/autophagy in microglia. We further showed that ATP6V0A1/a1 and TCIRG1/a3 subunits in mouse macrophages preferentially located in endosomes and lysosomes, respectively. Blocking these subunits disrupted early-to-late endosome transition and endosome-to-lysosome fusion, respectively. Taken together, our results highlight the essential and conserved roles played by different V-ATPase subunits in multiple steps of phagocytosis and endocytosis across various species.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping