The Purified and Recombinant Legionella pneumophila Chaperonin Alters Mitochondrial Trafficking and Microfilament Organization▿
AUTOR(ES)
Chong, Audrey
FONTE
American Society for Microbiology (ASM)
RESUMO
A portion of the total cellular pool of the Legionella pneumophila chaperonin, HtpB, is found on the bacterial cell surface, where it can mediate invasion of nonphagocytic cells. HtpB continues to be abundantly produced and released by internalized L. pneumophila and may thus have postinvasion functions. We used here two functional models (protein-coated beads and expression of recombinant proteins in CHO cells) to investigate the competence of HtpB in mimicking early intracellular trafficking events of L. pneumophila, including the recruitment of mitochondria, cytoskeletal alterations, the inhibition of phagosome-lysosome fusion, and association with the endoplasmic reticulum. Microscopy and flow cytometry studies indicated that HtpB-coated beads recruited mitochondria in CHO cells and U937-derived macrophages and induced transient changes in the organization of actin microfilaments in CHO cells. Ectopic expression of HtpB in the cytoplasm of transfected CHO cells also led to modifications in actin microfilaments similar to those produced by HtpB-coated beads but did not change the distribution of mitochondria. Association of phagosomes containing HtpB-coated beads with the endoplasmic reticulum was not consistently detected by either fluorescence or electron microscopy studies, and only a modest delay in the fusion of TrOv-labeled lysosomes with phagosomes containing HtpB-coated beads was observed. HtpB is the first Legionella protein and the first chaperonin shown to, by means of our functional models, induce mitochondrial recruitment and microfilament rearrangements, two postinternalization events that typify the early trafficking of virulent L. pneumophila.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2772529Documentos Relacionados
- Legionella pneumophila Catalase-Peroxidases Are Required for Proper Trafficking and Growth in Primary Macrophages
- IcmF and DotU Are Required for Optimal Effector Translocation and Trafficking of the Legionella pneumophila Vacuole
- Surface-Associated Hsp60 Chaperonin of Legionella pneumophila Mediates Invasion in a HeLa Cell Model
- Enzymatic activities of Legionella pneumophila and Legionella-like organisms.
- Photoreactivation of UV-irradiated Legionella pneumophila and other Legionella species.