Many maternally inherited and incurable neuromyopathies are caused by mutations in mitochondrial (mt) transfer RNA (tRNA) genes. Kinetoplastid protozoa, including Leishmania, have evolved specialized systems for importing nucleus-encoded tRNAs into mitochondria. We found that the Leishmania RNA import complex (RIC) could enter human cells by a caveolin-1–dependent pathway, where it induced import of endogenous cytosolic tRNAs, including tRNALys, and restored mitochondrial function in a cybrid harboring a mutant mt tRNALys (MT-TK) gene. The use of protein complexes to modulate mitochondrial function may help in the management of such genetic disorders.
1 Genetic Engineering, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Calcutta 700032, India.
2 Molecular Endocrinology, Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Calcutta 700032, Ind