Abstract
The mitochondrial genome of trypanosomes is composed of thousands of topologically interlocked circular DNA molecules that form the kinetoplast DNA (kDNA). Most genes encoded by the kDNA require a posttranscriptional modification process called RNA editing to form functional mRNAs. Here, we show that alternative editing of the mitochondrial cytochrome c oxidase III (COXIII) mRNA in Trypanosoma brucei produces a novel DNA binding protein, alternatively edited protein 1 (AEP-1). AEP-1 localizes to the region of the cell between the kDNA and the flagellum and purifies with the tripartite attachment complex, a structure believed to physically link the kDNA and flagellar basal bodies. Expression of the DNA binding domain of AEP-1 results in aberrant kDNA structure and reduced cell growth, indicating that AEP-1 is involved in the maintenance of the kDNA. Perhaps most important, our studies show a gain of function through an alternatively edited mRNA and, for the first time, provide a link between the unusual structure of the kDNA and RNA editing in trypanosome mitochondria.
Publication types
-
Research Support, N.I.H., Extramural
MeSH terms
-
Alternative Splicing*
-
Amino Acid Sequence
-
Animals
-
Cell Line
-
DNA, Mitochondrial / genetics
-
DNA, Mitochondrial / metabolism*
-
DNA-Binding Proteins / chemistry
-
DNA-Binding Proteins / genetics*
-
DNA-Binding Proteins / metabolism
-
Electron Transport Complex IV / chemistry
-
Electron Transport Complex IV / genetics
-
Electron Transport Complex IV / metabolism
-
Mitochondria / genetics
-
Mitochondria / metabolism
-
Mitochondria / ultrastructure
-
Models, Molecular
-
Molecular Sequence Data
-
Phenotype
-
Protein Conformation
-
Protozoan Proteins / chemistry
-
Protozoan Proteins / genetics*
-
Protozoan Proteins / metabolism
-
RNA Editing*
-
RNA, Guide, Kinetoplastida / chemistry
-
RNA, Guide, Kinetoplastida / genetics
-
RNA, Guide, Kinetoplastida / metabolism*
-
Recombinant Fusion Proteins / chemistry
-
Recombinant Fusion Proteins / genetics
-
Recombinant Fusion Proteins / metabolism
-
Trypanosoma brucei brucei / cytology*
-
Trypanosoma brucei brucei / genetics*
-
Trypanosoma brucei brucei / metabolism
Substances
-
DNA, Mitochondrial
-
DNA-Binding Proteins
-
Protozoan Proteins
-
Recombinant Fusion Proteins
-
Electron Transport Complex IV
-
RNA, Guide, Kinetoplastida