Mitochondrial tRNA import is widespread. Yet, the mechanism that determines its specificity is unknown. The mitochondrial genome of Trypanosoma brucei does not encode any tRNAs, trypanosomes are therefore an excellent system to study the process. The Northern blot above shows that ablation of cytosolic elongation factor 1a (eEF1a) inhibits mitochondrial import of newly synthesized tRNAs. Thus, for a tRNA to be imported into the mitochondrion of T. brucei, it needs to bind eEF1a, and it is this interaction that mediates the import specificity.

This work was carried out in the group of Prof. André Schneider.

References:

• N. Bouzaidi-Tiali, E. Aeby, F. Charrière, M. Pusnik, A. Schneider;
  "Elongation factor 1a mediates the specificity of mitochondrial tRNA import in T. brucei"
  EMBO J., 26, 4302-4312, (2007); doi:10.1038/sj.emboj.7601857.