| Content Provider |
World Health Organization (WHO)-Global Index Medicus |
| Author |
Ichihara, Atsuhiro Hermsen, Christina Lee, Beth S. De Brabander, Jef Saftig, Paul Schwake, Michael Von Bargen, Kristine Haas, Albert Griffiths, Gareth Nesset, Cecilie Kåsi Kissing, Sandra Repnik, Urska |
| Description |
Author Affiliation: Kissing S ( From the Institute of Biochemistry, Christian-Albrechts-University of Kiel, D-24098 Kiel, Germany.); Hermsen C ( Institute for Cell Biology, Friedrich-Wilhelms University, D-53121 Bonn, Germany.); Repnik U ( Department of Biosciences, University of Oslo, 0316 Oslo, Norway.); Nesset CK ( Department of Biosciences, University of Oslo, 0316 Oslo, Norway.); von Bargen K ( Institute for Cell Biology, Friedrich-Wilhelms University, D-53121 Bonn, Germany.); Griffiths G ( Department of Biosciences, University of Oslo, 0316 Oslo, Norway.); Ichihara A ( Department of Medicine II, Tokyo Women's Medical University, Tokyo 162-866, Japan.); Lee BS ( Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio 42210.); Schwake M ( Department of Chemistry, Biochemistry III, University of Bielefeld, D-33615 Bielefeld, Germany, and.); De Brabander J ( Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390.); Haas A ( Institute for Cell Biology, Friedrich-Wilhelms University, D-53121 Bonn, Germany, albert.haas@uni-bonn.de.); Saftig P ( From the Institute of Biochemistry, Christian-Albrechts-University of Kiel, D-24098 Kiel, Germany, psaftig@biochem.uni-kiel.de.) |
| Abstract |
The vacuolar H(+)-ATPase (v-ATPase) complex is instrumental in establishing and maintaining acidification of some cellular compartments, thereby ensuring their functionality. Recently it has been proposed that the transmembrane V0 sector of v-ATPase and its a-subunits promote membrane fusion in the endocytic and exocytic pathways independent of their acidification functions. Here, we tested if such a proton-pumping independent role of v-ATPase also applies to phagosome-lysosome fusion. Surprisingly, endo(lyso)somes in mouse embryonic fibroblasts lacking the V0 a3 subunit of the v-ATPase acidified normally, and endosome and lysosome marker proteins were recruited to phagosomes with similar kinetics in the presence or absence of the a3 subunit. Further experiments used macrophages with a knockdown of v-ATPase accessory protein 2 (ATP6AP2) expression, resulting in a strongly reduced level of the V0 sector of the v-ATPase. However, acidification appeared undisturbed, and fusion between latex bead-containing phagosomes and lysosomes, as analyzed by electron microscopy, was even slightly enhanced, as was killing of non-pathogenic bacteria by V0 mutant macrophages. Pharmacologically neutralized lysosome pH did not affect maturation of phagosomes in mouse embryonic cells or macrophages. Finally, locking the two large parts of the v-ATPase complex together by the drug saliphenylhalamide A did not inhibit in vitro and in cellulo fusion of phagosomes with lysosomes. Hence, our data do not suggest a fusion-promoting role of the v-ATPase in the formation of phagolysosomes. |
| ISSN |
00219258 |
| e-ISSN |
1083351X |
| Journal |
Journal of Biological Chemistry |
| Issue Number |
22 |
| Volume Number |
290 |
| Language |
English |
| Publisher |
American Society for Biochemistry and Molecular Biology (United States) |
| Publisher Date |
2015-05-29 |
| Publisher Place |
United States |
| Access Restriction |
Open |
| Subject Keyword |
Lysosomes Metabolism Phagosomes Proton-Translocating ATPases Receptors, Cell Surface Vacuolar Proton-Translocating ATPases Animals Escherichia Coli Fibroblasts Hydrogen-Ion Concentration Macrophages Cytology Microbiology Membrane Fusion Mice Mice, Knockout Mice, Transgenic Microscopy, Electron Microscopy, Fluorescence Subcellular Fractions Research Support, Non-U.S. Gov't Biochemistry Molecular Biology |
| Content Type |
Text |
| Resource Type |
Article |
| Subject |
Cell Biology Biochemistry Molecular Biology |
