Subcellular Localization and Cytotoxic Activity of the GroEL-Like Protein Isolated from Actinobacillus actinomycetemcomitans
AUTOR(ES)
Goulhen, F.
FONTE
American Society for Microbiology
RESUMO
The subcellular locations, ultrastructure, and cytotoxic activity of the GroEL-like protein from Actinobacillus actinomycetemcomitans were investigated. Two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) clearly indicated that synthesis of the GroEL-like protein is substantially increased after a thermal shock. Analysis of the purified native GroEL-like protein by transmission electron microscopy revealed the typical 14-mer cylindrical molecule, which had a diameter of about 12 nm. A. actinomycetemcomitans cells grown at 35°C and heat shocked at 43°C were fractionated, and fractions were separated by SDS-PAGE and analyzed by Western immunoblotting using antibodies to GroEL- and DnaK-like proteins. The GroEL-like protein was found in both the soluble and membrane fractions, whereas the DnaK-like protein was mostly found in the cytoplasm. An increase in specific proteins, including the GroEL- and DnaK-like proteins, was found in heat-shocked cells. The subcellular localization of the GroEL-like protein was examined by immunoelectron microscopy of whole cells. More GroEL-like protein was detected in stressed cells than in unstressed cells, and most of it was found not directly associated with outer membranes but rather in extracellular material. The native GroEL-like protein was assessed for cytotoxic activities. The GroEL-like protein increased the proliferation of periodontal ligament epithelial cells at concentrations between 0.4 and 1.0 μg/ml. The number of cells in the culture decreased significantly at higher concentrations. A cell viability assay using HaCaT epithelial cells indicated that the GroEL-like protein was strongly toxic for the cells. These studies suggest the extracellular nature of the GroEL-like protein and its putative role in disease initiation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=108663Documentos Relacionados
- Purification and immunological characterization of a GroEL-like protein from Bordetella pertussis.
- Characterization of the groEL-like genes in Streptomyces albus.
- A survey of the heat shock response in four Streptomyces species reveals two groEL-like genes and three groEL-like proteins in Streptomyces albus.
- The potent bone-resorbing mediator of Actinobacillus actinomycetemcomitans is homologous to the molecular chaperone GroEL.
- Identification and characterization of genetic cluster groups of Actinobacillus actinomycetemcomitans isolated from the human oral cavity.