INVESTIGADORES
COLOMBO Maria Isabel
artículos
Título:
Endocytic SNAREs are involved in optimal Coxiella burnetii vacuole development?. Cell Microbiol. 2012 Dec 6. doi: 10.1111/cmi.12087 (in press).
Autor/es:
CAMPOY, E.; MANSILLA, M.E.; COLOMBO M.I.
Revista:
CELLULAR MICROBIOLOGY (PRINT)
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012
ISSN:
1462-5814
Resumen:
Coxiella burnetii is a Gram-negative intracellular
bacterium. As previously described, both the
endocytic and the autophagic pathways contribute
to the maturation of Coxiella replicative vacuoles
(CRVs). The large CRVs share the properties of
both phagolysosomal and autophagolysosomal
compartments. Vamp3, Vamp7 and Vamp8 are
v-SNAREs involved in the endocytic pathway
which participate mainly in the fusion between
endosomes and lysosomes. In the present study
we observed that Vamp7 interacts with C. burnetiiis a Gram-negative intracellular
bacterium. As previously described, both the
endocytic and the autophagic pathways contribute
to the maturation of Coxiella replicative vacuoles
(CRVs). The large CRVs share the properties of
both phagolysosomal and autophagolysosomal
compartments. Vamp3, Vamp7 and Vamp8 are
v-SNAREs involved in the endocytic pathway
which participate mainly in the fusion between
endosomes and lysosomes. In the present study
we observed that Vamp7 interacts with C. burnetiiCoxiella replicative vacuoles
(CRVs). The large CRVs share the properties of
both phagolysosomal and autophagolysosomal
compartments. Vamp3, Vamp7 and Vamp8 are
v-SNAREs involved in the endocytic pathway
which participate mainly in the fusion between
endosomes and lysosomes. In the present study
we observed that Vamp7 interacts with C. burnetiiC. burnetii
at different infection times (1 h?48 h p.i.). We have
determined that a truncated mutant of Vamp7
(Vamp7 NT) and a siRNA against this SNARE
protein affects the optimal development of CRVs,
suggesting that Vamp7 mediates fusion events
that are required for the biogenesis of CRVs.
Indeed, we have observed that overexpression of
Vamp7 NT inhibited the heterotypic fusion with
lysosomes and the homotypic fusion between individual
Coxiella phagosomes and CRVs. Moreover,
we have detected in the vacuole membrane, at
different infection times, the Vamp7 partners (Vti1a
and Vti1b). Interestingly, treatment with chloramphenicol
reduced the colocalization betweenphagosomes and CRVs. Moreover,
we have detected in the vacuole membrane, at
different infection times, the Vamp7 partners (Vti1a
and Vti1b). Interestingly, treatment with chloramphenicol
reduced the colocalization between
C. burnetii and Vamp7, Vti1a or Vti1b, indicating
that the recruitment of these SNAREs proteins is a
bacteria-driven process that favours the CRV biogenesis,
likely by facilitating the interaction with
the endolysosomal compartment.and Vamp7, Vti1a or Vti1b, indicating
that the recruitment of these SNAREs proteins is a
bacteria-driven process that favours the CRV biogenesis,
likely by facilitating the interaction with
the endolysosomal compartment.