TCDJ1, A PUTATIVE MITOCHONDRIAL DNAJ PROTEIN IN TRYPANSOMA-CRUZI

A full length cDNA encoding a novel Trypanosoma cruzi DnaJ protein was cloned and characterized. The 324 amino acid protein encoded by the c DNA (TcDJ1) displays a characteristic J-domain, but lacks the Gly-Phe and zinc finger regions present in some other DnaJ proteins. Relative to four other T. cruzi DnaJ proteins, TcDJ1 has an amino terminal exte nsion containing basic and hydroxylated residues characteristic of mit ochondrial import peptides. A T. cruzi transfectant expressing epitope -tagged TcDJ1 was generated and subcellular fractions were produced. W estern blot analysis revealed that the protein has a molecular mass of 29 kDa and is found in the mitochondrial fraction. The expression of TcDJ1 is developmentally regulated since the levels of both mRNA and p rotein are much higher in epimastigotes (replicative form) than in met acyclic trypomastigotes (infective form). Thus it may participate in m itochondrial biosynthetic processes in this organism. (C) 1998 Federat ion of European Microbiological Societies. Published by Elsevier Scien ce B.V. All rights reserved.