5 S rRNA and tRNA import into human mitochondria. Comparison of in vitro requirements.

摘要: In vivo, human mitochondria import 5 S rRNA and do not tRNAs from the cytoplasm. We demonstrated previously that isolated are able to internalize a yeast tRNA(Lys) in presence of soluble factors. Here, we describe an assay for specific uptake by compare its requirements with artificial tRNA import. The efficiency was comparable found vivo. shown depend on ATP transmembrane electrochemical potential directed proteins. Blocking pre-protein channel inhibited internalization both tRNA, which suggests this apparatus be involved RNA mitochondria. show can also selectively several vitro synthesized versions as well transcript mitochondrial tRNA(Lys). Either or proteins direct import, suggesting cells possess all factors needed such translocation. On other hand, protein varies significantly, depending version. Similarly system, into depended aminoacylation precursor lysyl-tRNA synthetase. dependent upon protein(s), were distinct providing internalization.