Autophagy across the eukaryotes: is S. cerevisiae the odd one out?

Abstract

Autophagy is conserved throughout the eukaryotes and for many years, work in Saccharomyces cerevisiae has been at the forefront of autophagy research. However as our knowledge of the autophagic machinery has increased, differences between S. cerevisiae and mammalian cells have become apparent. Recent work in other organisms, such as the amoeba Dictyostelium discoideum, indicate an autophagic pathway much more similar to mammalian cells than S. cerevisiae, despite its earlier evolutionary divergence. S. cerevisiae therefore appear to have significantly specialized, and the autophagic pathway in mammals is much more ancient than previously appreciated, which has implications for how we interpret data from organisms throughout the eukaryotic tree.

Keywords: Dictyostelium; S. cerevisiae; Saccharomyces; autophagy; evolution; omegasomes.

Figure 1. A simplified eukaryotic tree. This phylogeny is based on references and and nearly all eukaryotes can be placed in one of the eight groups. The organisms named were used as representatives of each clade to search for the presence of autophagy-related genes. The Cercozoa have been excluded from the sequence analysis due the lack of complete genomic data.