Cellular vacuoles induced by Mycoplasma pneumoniae CARDS toxin originate from Rab9-associated compartments.
PLoS One
; 6(7): e22877, 2011.
Article
en En
| MEDLINE
| ID: mdl-21829543
ABSTRACT
Recently, we identified an ADP-ribosylating and vacuolating cytotoxin in Mycoplasma pneumoniae designated Community Acquired Respiratory Distress Syndrome (CARDS) toxin. In this study we show that vacuoles induced by recombinant CARDS (rCARDS) toxin are acidic and derive from the endocytic pathway as determined by the uptake of neutral red and the fluid-phase marker, Lucifer yellow, respectively. Also, we demonstrate that the formation of rCARDS toxin-associated cytoplasmic vacuoles is inhibited by the vacuolar ATPase inhibitor, bafilomycin A1, and the ionophore, monensin. To examine the ontogeny of these vacuoles, we analyzed the distribution of endosomal and lysosomal membrane markers during vacuole formation and observed the enrichment of the late endosomal GTPase, Rab9, around rCARDS toxin-induced vacuoles. Immunogold-labeled Rab9 and overexpression of green fluorescent-tagged Rab9 further confirmed vacuolar association. The late endosomal- and lysosomal-associated membrane proteins, LAMP1 and LAMP2, also localized to the vacuolar membranes, while the late endosomal protein, Rab7, and early endosomal markers, Rab5 and EEA1, were excluded. HeLa cells expressing dominant-negative (DN) Rab9 exhibited markedly reduced vacuole formation in the presence of rCARDS toxin, in contrast to cells expressing DN-Rab7, highlighting the importance of Rab9 function in rCARDS toxin-induced vacuolation. Our findings reveal the unique Rab9-association with rCARDS toxin-induced vacuoles and its possible relationship to the characteristic histopathology that accompanies M. pneumoniae infection.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Endosomas
/
Proteínas Bacterianas
/
Toxinas Bacterianas
/
Vacuolas
/
Proteínas de Unión al GTP rab
/
Lisosomas
Tipo de estudio:
Prognostic_studies
/
Risk_factors_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos