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Characterization of mitochondrial outer membrane proteins involved in mitochondrial protein import in Trypanosoma brucei
Author(s) -
Sharma Shvetank,
Singha Ujjal K,
Chaudhuri Minu
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.813.2
Subject(s) - trypanosoma brucei , biology , tetratricopeptide , mitochondrial carrier , microbiology and biotechnology , rna interference , mitochondrion , inner mitochondrial membrane , translocase of the inner membrane , protein targeting , atp–adp translocase , biochemistry , mitochondrial membrane transport protein , membrane protein , bacterial outer membrane , rna , gene , membrane , escherichia coli
Mitochondrial protein translocation machinery in parasites like Trypanosoma brucei is poorly characterized. Homologs for components of the translocase of mitochondrial outer membrane (TOM) in T. brucei are not known. Major component of the TOM complex in eukaryotes is Tom40. TOM complex also has two tetratricopeptide repeat containing proteins, Tom70 and Tom20 (receptors for mitochondrial precursor proteins). We identified two β‐barrel proteins from T. brucei gene database. Analysis of the subcellular fractions of T. brucei using antibodies developed against peptides from these proteins revealed that these are localized on the mitochondrial membrane. RNA interference studies showed that both these proteins are essential for cell growth in the procyclic T. brucei . We also identified three TPR containing proteins named TPR5, TPR7, TPR9 showed some homology to Tom70 of various species. The effect of expression of RNAi on cell growth and morphology was monitored for each of the proteins individually. Results showed that RNAi for TPR5 and TPR7 had little effect on cell growth. However, RNAi for TPR9 caused more than 70% inhibition of cell growth within 4 days in culture. In addition TPR9 knock‐down also changed the cell morphology. Further analysis of the functions of all the candidate proteins is under investigation. Grant Support: 3SO6GM08037‐30S1 and 1SC1GM081146‐01.