Missing the Subcellular Target: A Mechanism of Eukaryotic Gene Evolution

Abstract

Gene duplication is a critical force in genome evolution. By serving as the raw material for new genetic functions, duplications are believed to lead to the evolution of new genes and genetic innovations. The increasing availability of genomic data reveals that gene duplication through polyploidization or other mechanisms is prevalent in genomes from across all three domains of life. Elucidating the mechanisms by which duplicated genes acquire novel functions is a key question in genome evolution. We propose that one such mechanism is protein subcellular relocalization (PSR), where small changes to N-terminal signal peptides lead to differential targeting of otherwise identical duplicated proteins. We argue that changing the location of duplicate proteins within the eukaryotic cell can lead to novel functions. If these new functions are advantageous, these duplicates would then be retained as novel genes. We suggest that PSR is an important evolutionary mechanism and that it has played an influential role in the origin of new eukaryotic genes.