title: Mobility of late endosomal and lysosomal markers on phagosomes analyzed by fluorescence recovery after photobleaching.
abstract: During phagosome maturation, the late endosomal marker Rab7 and the lysosomal marker LAMP1 localize to the phagosomes. We investigated the mobility of Rab7 and LAMP1 on the phagosomes in macrophages by fluorescence recovery after photobleaching (FRAP) analysis. Rab7 was mobile between the phagosomal membrane and the cytosol in macrophages that ingested latex beads during phagosome maturation. The addition of interferon-γ (IFN-γ) restricted this mobility, suggesting that Rab7 is forced to bind to the phagosomal membrane by IFN-γ-mediated activation. Immobilization of LAMP1 on the phagosomes was observed irrespective of IFN-γ-activation. We further examined the mobility of Rab7 on the phagosomes containing Mycobacterium bovis BCG by FRAP analysis. The rate of fluorescence recovery for Rab7 on mycobacterial phagosomes was lower than that on the phagosomes containing latex beads, suggesting that mycobacteria impaired the mobility of Rab7 and arrested phagosome maturation.
authors.affiliation: Department of Health Science, Hamamatsu University School of Medicine, 1-20-1 Handa-yama, Higashi-ku, Hamamatsu 431-3192, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Sugaya
authors.forename: Shintaro
authors.initials: S
authors.lastname: Seto
authors.forename: Kunio
authors.initials: K
authors.lastname: Tsujimura
authors.forename: Yukio
authors.initials: Y
authors.lastname: Koide
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002460:Cell Line; D011992:Endosomes / Q000378:metabolism* / Q000382:microbiology; D036681:Fluorescence Recovery After Photobleaching; D007371:Interferon-gamma / Q000494:pharmacology; D051907:Lysosomal Membrane Proteins / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D051379:Mice; D008863:Microspheres; D009163:Mycobacterium bovis / Q000276:immunology; D010588:Phagosomes / Q000378:metabolism* / Q000382:microbiology; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000090802:rab7 GTP-Binding Proteins; D052118:Lysosomal-Associated Membrane Protein 1
chemical_list: D015415:Biomarkers; D007371:Interferon-gamma; D051907:Lysosomal Membrane Proteins; D020691:rab GTP-Binding Proteins; D000090802:rab7 GTP-Binding Proteins; C052255:Lamp1 protein, mouse; D052118:Lysosomal-Associated Membrane Protein 1; C000716465:rab7 GTP-binding proteins, mouse