From endosymbiont to host-controlled organelle: the hijacking of mitochondrial protein synthesis and metabolism.
Mitochondria are eukaryotic organelles that originated from the endosymbiosis of an alpha-proteobacterium. To gain insight into the evolution of the mitochondrial proteome as it proceeded through the transition from a free-living cell to a specialized organelle, we compared a reconstructed ancestral proteome of the mitochondrion with the proteomes of alpha-proteobacteria as well as with the mitochondrial proteomes in yeast and man. Overall, there has been a large turnover of the mitochondrial proteome during the evolution of mitochondria. Early in the evolution of the mitochondrion, proteins involved in cell envelope synthesis have virtually disappeared, whereas proteins involved in replication, transcription, cell division, transport, regulation, and signal transduction have been replaced by eukaryotic proteins. More than half of what remains from the mitochondrial ancestor in modern mitochondria corresponds to translation, including post-translational modifications, and to metabolic pathways that are directly, or indirectly, involved in energy conversion. Altogether, the results indicate that the eukaryotic host has hijacked the proto-mitochondrion, taking control of its protein synthesis and metabolism.
Gabaldón
Toni
T
Nijmegen Center for Molecular Life Sciences, Center for Molecular and Biomolecular Informatics, University of Nijmegen, Nijmegen, The Netherlands. tgabaldon@cipf.es
Huynen
Martijn A
MA
D005075:Biological Evolution; D003198:Computer Simulation; D004252:DNA Mutational Analysis / Q000379:methods; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000502:physiology*; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D008928:Mitochondria / Q000502:physiology*; D024101:Mitochondrial Proteins / Q000502:physiology*; D008957:Models, Genetic; D015388:Organelles / Q000502:physiology; D014176:Protein Biosynthesis / Q000235:genetics*; D013559:Symbiosis / Q000235:genetics*
D005656:Fungal Proteins; D024101:Mitochondrial Proteins