The Hsp90 chaperone system from the African trypanosome, Trypanosoma brucei

Abstract

African Trypanosomiasis is a neglected tropical disease caused by Trypanosoma brucei (T. brucei) and is spread by the tsetse fly in sub-Saharan Africa. The disease is fatal if left untreated and the currently approved drugs for treatment are toxic and difficult to administer. The trypanosome must survive in the insect vector and its mammalian host, and to adapt to these different conditions, the parasite relies on molecular chaperones called heat shock proteins. Heat shock proteins mediate the folding of newly synthesized proteins as well as prevent misfolding of proteins under normal conditions and during stressful conditions. Heat shock protein 90 (Hsp90) is one of the major molecular chaperones of the stress response at the cellular level. It functions with other chaperones and co-chaperones and inhibition of its interactions is being explored as a potential therapeutic target for numerous diseases. This study provides an in-silico overview of Hsp90 and its co-chaperones in both T. brucei brucei and T. brucei gambiense in relation to human and other kinetoplastid parasites. The evolutionary, functional, and structural analyses of Hsp90 were also shown. The updated information on Hsp90 and its co-chaperones from recently published proteomics on T. brucei was examined for the different life cycle stages and subcellular localisations. The results show a difference between T. b. brucei and T. b. gambiense with T. b. brucei encoding 12 putative Hsp90 genes, 10 of which are cytosolic and located on a single chromosome while T. gambiense encodes 5 Hsp90 genes, 3 of which are located in the cytosol. Eight putative co-chaperones were identified in this study, 6 TPR-containing and 2 non-TPR-containing co-chaperones. This study provides an updated context for studying the biology of the African trypanosome and evaluating Hsp90 and its interactions as potential drug targets.