Evolutionary proteomics in yeasts

 

Using Saccharomyces budding yeast species as models, I studied the evolutionary processes that modify protein interaction networks. I looked especially at the ways in which they diverge between closely related species and are reshuffled in interspecific hybrids.

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In the two related, but reproductively isolated, species S. cerevisiae and S. kudriavzevii, I found the experimental evidence that protein complexes that perform essential cellular functions are highly conserved between species, despite extensive protein divergence, and remain unperturbed in hybrids. 

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Using genomic and proteomic data available for these two species, and the powerful Protein-Fragment Complementation assay technology to measure protein-protein interactions (PPIs) in vivo, I showed that protein divergence was counterbalanced by the high conservation of a few protein residues involved in PPIs and that the few PPI differences we did observe between both species were likely due to amino-acid divergence in these residues.

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This study will shed light on a new level of molecular mechanisms underlying cellular disorders, such as cell proliferation or apoptosis, with potential applications for human medical research.

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Link: Labo Landry - Université Laval, Québec (Canada)