Expression and subcellular localization of cpn60 protein family members inLeishmania donovani

We have identified two diverged members of the cpn60 gene family in Leishma nia donovani, causative agent of Indian Kala Azar. One of the genes, cpn60. 1, although actively transcribed, is not expressed to detectable levels of protein in cultured L. donovani. The other gene, cpn60.2, which, compared w ith cpn60.1, shows a higher sequence conservation with the hsp60 genes from Trypanosoma brucei and Trypanosoma cruzi is expressed constitutively in cu ltured promastigotes. The abundance of the gene product, Cpn60.2, increases by 2.5-fold under heat stress and in axenic amastigotes of L. donovani. Cp n60.2 is also found enriched in mitochondrial cell fractions and localizes to the mitochondrial matrix. We conclude that Cpn60.2 is the major mitochon drial chaperonin in Leishmania. (C) 2000 Elsevier Science B.V. All rights r eserved.