Mitochondrial lysyl-tRNA synthetase independent import of tRNA lysine into yeast mitochondria

PLoS One. 2012;7(4):e35321. doi: 10.1371/journal.pone.0035321. Epub 2012 Apr 23.

Abstract

Aminoacyl tRNA synthetases play a central role in protein synthesis by charging tRNAs with amino acids. Yeast mitochondrial lysyl tRNA synthetase (Msk1), in addition to the aminoacylation of mitochondrial tRNA, also functions as a chaperone to facilitate the import of cytosolic lysyl tRNA. In this report, we show that human mitochondrial Kars (lysyl tRNA synthetase) can complement the growth defect associated with the loss of yeast Msk1 and can additionally facilitate the in vitro import of tRNA into mitochondria. Surprisingly, the import of lysyl tRNA can occur independent of Msk1 in vivo. This suggests that an alternative mechanism is present for the import of lysyl tRNA in yeast.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Lysine-tRNA Ligase / genetics
  • Lysine-tRNA Ligase / metabolism*
  • Mitochondria / enzymology*
  • RNA, Transfer, Lys / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Ribosomal Protein S6 Kinases, 90-kDa / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism

Substances

  • RNA, Transfer, Lys
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Ribosomal Protein S6 Kinases, 90-kDa
  • mitogen and stress-activated protein kinase 1
  • Lysine-tRNA Ligase