Protein synthesis in mitochondria isolated from the trypanosomatid protozoan Crithidia fasciculata

Evidence presented over the years in support of mitochondrial translation in trypanosomes, based largely on studies using differential inhibitors such as cycloheximide and chloramphenicol, remains controversial. I have studied endogenous mRNA-dependent translation in a mitochondrial fraction isolated from the trypanosomatid protozoan Crithidia fasciculata. By using pancreatic ribonuclease to inactivate contaminating cytosolic activity, I show that these mitochondria can conduct protein synthesis in their own right. The mitochondrial translational products differed from cytosolic products as judged by SDS-PAGE, and had sizes expected of some proteins encoded in the mitochondrial genome of C. fasciculata and other trypanosomatids. Some evidence is provided suggesting that the seat of translation might be the kinetoplast.