Dissection of Rab7 localization on Mycobacterium tuberculosis phagosome.
The late endosomal marker Rab7 has been long believed to be absent from the phagosome containing Mycobacterium tuberculosis (M.tb) in macrophage, but the detail kinetics remains elusive. Here, we found that Rab7 is transiently recruited to and subsequently released from M.tb phagosomes. For further understanding of the effect of Rab7 dissociation from the phagosome, we examined the localization of lysosomal markers on the phagosome in the macrophage expressing a dominant-negative Rab7. The localization of lysosomal associated membrane protein-2 (LAMP-2) on the phagosome was Rab7-independent, while that of cathepsin D was Rab7-dependent. These results agree with the localization of each lysosomal marker on M.tb phagosome at 6h postinfection-i.e., LAMP-2, but not cathepsin D localized on the majority of M.tb phagosomes. These results suggest that the dissociation of Rab7 from M.tb phagosome is the important process in inhibition of phagolysosome biogenesis.
Seto
Shintaro
S
Department of Infectious Diseases, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
Matsumoto
Sohkichi
S
Ohta
Isamu
I
Tsujimura
Kunio
K
Koide
Yukio
Y
D000818:Animals; D002460:Cell Line; D006801:Humans; D008264:Macrophages / Q000382:microbiology* / Q000648:ultrastructure; D051379:Mice; D009169:Mycobacterium tuberculosis; D010588:Phagosomes / Q000201:enzymology*; D020691:rab GTP-Binding Proteins / Q000378:metabolism*; D000090802:rab7 GTP-Binding Proteins
D000090802:rab7 GTP-Binding Proteins; C000716463:rab7 GTP-binding proteins, human; C000716465:rab7 GTP-binding proteins, mouse; D020691:rab GTP-Binding Proteins