Virulence and Functions of Myosin II Are Inhibited by Overexpression of Light Meromyosin in Entamoeba histolytica
AUTOR(ES)
Arhets, Philippe
FONTE
The American Society for Cell Biology
RESUMO
Several changes in cell morphology take place during the capping of surface receptors in Entamoeba histolytica. The amoebae develop the uroid, an appendage formed by membrane invaginations, which accumulates ligand–receptor complexes resulting from the capping process. Membrane shedding is particularly active in the uroid region and leads to the elimination of accumulated ligands. This appendage has been postulated to participate in parasitic defense mechanisms against the host immune response, because it eliminates complement and specific antibodies bound to the amoeba surface. The involvement of myosin II in the capping process of surface receptors has been suggested by experiments showing that drugs that affect myosin II heavy-chain phosphorylation prevent this activity. To understand the role of this mechanoenzyme in surface receptor capping, a myosin II dominant negative strain was constructed. This mutant is the first genetically engineered cytoskeleton-deficient strain of E. histolytica. It was obtained by overexpressing the light meromyosin domain, which is essential for myosin II filament formation. E. histolytica overexpressing light meromyosin domain displayed a myosin II null phenotype characterized by abnormal movement, failure to form the uroid, and failure to undergo the capping process after treatment with concanavalin A. In addition, the amoebic cytotoxic capacities of the transfectants on human colon cells was dramatically reduced, indicating a role for cytoskeleton in parasite pathogenicity.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=25380Documentos Relacionados
- Flexibility of myosin rod, light meromyosin, and myosin subfragment-2 in solution.
- Myosin II is involved in capping and uroid formation in the human pathogen Entamoeba histolytica.
- Correlation of Virulence and Collagenolytic Activity in Entamoeba histolytica
- Localization of myosin heavy chain A in the human pathogen Entamoeba histolytica.
- Entamoeba histolytica Expressing a Dominant Negative N-Truncated Light Subunit of Its Gal-Lectin Are Less Virulent