Causes and consequences of mitochondrial proteome size variation in animals

Abstract

Despite a conserved set of core mitochondrial functions, animal mitochondrial proteomes show a large variation in size. We analyzed putative mechanisms behind and functional significance of this variation by performing comparative analysis of the experimentally-verified mitochondrial proteomes of four bilaterian animals (human, mouse, Caenorhabditis elegans, and Drosophila melanogaster) and two non-animal outgroups (Acanthamoeba castellanii and Saccharomyces cerevisiae). We found that of several factors affecting mitochondrial proteome size, evolution of novel mitochondrial proteins in mammals and loss of ancestral proteins in protostomes were the main contributors. Interestingly, the gain and loss of the N-terminal mitochondrial targeting signal was not a major factor in the proteome size evolution.

Keywords: Mitochondria; Mitochondrial-targeting-signals; Proteome.