TRYPANOSOMA-BRUCEI - MOLECULAR-CLONING AND STAGE-REGULATED EXPRESSIONOF A MALATE-DEHYDROGENASE LOCALIZED TO THE MITOCHONDRION

African trypanosomes exhibit dramatic developmental changes in carbohy drate and energy metabolism, with cytochrome-mediated respiration play ing an important role only in the insect stages. The parasites possess three isozymes of malate dehydrogenase, each of which has a different subcellular localization and, likely, a distinct metabolic role. We h ave cloned and characterized a cDNA encoding one of these malate dehyd rogenases. Epitope tagging and transfection experiments demonstrate th at the corresponding protein is localized to the mitochondrion and tha t an intact amino terminus is required for proper compartmentalization . The abundance of transcript is developmentally regulated, with highe r levels in procyclic stage parasites. (C) 1998 Academic Press.