ATPase-associated oligomycin resistance in Acanthamoeba castellanii

Area of Science:

• Microbiology
• Cell Biology
• Biochemistry

Background:

• Acanthamoeba castellanii is a protozoan parasite.
• Oligomycin is an antifungal antibiotic that inhibits mitochondrial ATP synthase.

Purpose of the Study:

• To investigate the mechanism of oligomycin resistance in Acanthamoeba castellanii.
• To characterize the oligomycin sensitivity of wild-type and resistant cell lines.

Main Methods:

• Comparing the multiplication rates of wild-type and OliR2 Acanthamoeba castellanii populations in the presence of varying oligomycin concentrations.
• Assessing the oligomycin sensitivity of solubilized mitochondrial ATPase from both cell lines.

Main Results:

• Wild-type Acanthamoeba castellanii multiplication was inhibited by 50% at approximately 3 microgram oligomycin/ml.
• The OliR2 resistant cell line required approximately 27 microgram/ml oligomycin for 50% growth inhibition.
• Mitochondrial ATPase from OliR2 fractions showed 3-10 fold higher resistance to oligomycin inhibition compared to wild-type.

Conclusions:

• Oligomycin resistance in Acanthamoeba castellanii is associated with altered mitochondrial ATPase sensitivity.
• The findings suggest a specific molecular adaptation in the mitochondrial ATPase of resistant strains.