Direct recruitment of H+-ATPase from lysosomes for phagosomal acidification.
The nascent phagosome progressively establishes an acidic milieu by acquiring a proton pump, the vacuolar-type ATPase (V-ATPase). However, the origin of phagosomal V-ATPase remains poorly understood. We found that phagosomes were enriched with the V-ATPase a3 subunit, which also accumulated in late endosomes and lysosomes. We modified the mouse Tcirg1 locus encoding subunit a3, to express an a3-GFP fusion protein. Live-cell imaging and immunofluorescence microscopy revealed that nascent phagosomes received the a3-GFP from tubular structures extending from lysosomes located in the perinuclear region. Macrophages from a3-deficient mice exhibited impaired acidification of phagosomes and delayed digestion of bacteria. These results show that lysosomal V-ATPase is recruited directly to the phagosomes via tubular lysosomes to establish the acidic environment hostile to pathogens.
Sun-Wada
Ge-Hong
GH
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kohdo, Kyotanabe, Kyoto 610-0395, Japan.
Tabata
Hiroyuki
H
Kawamura
Nobuyuki
N
Aoyama
Minako
M
Wada
Yoh
Y
D000818:Animals; D002478:Cells, Cultured; D006863:Hydrogen-Ion Concentration; D008247:Lysosomes / Q000201:enzymology* / Q000382:microbiology; D017737:Macrophages, Peritoneal / Q000201:enzymology* / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D010587:Phagocytosis; D010588:Phagosomes / Q000201:enzymology* / Q000382:microbiology; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013997:Time Factors; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*
C484226:Atp6ap1 protein, mouse; D011993:Recombinant Fusion Proteins; D025262:Vacuolar Proton-Translocating ATPases