Frequent assembly of chimeric complexes in the protein interaction network of an interspecies yeast hybrid

Abstract

Hybrids between species often show extreme phenotypes. The molecular determinants underlying such phenotypes are yet to be comprehensively explored. In this study, we investigated the phenotypes of an interspecies diploid hybrid in terms of protein-protein interactions detected by protein correlation profiling. We used two yeast species, Saccharomyces cerevisiae and Saccharomyces uvarum , which are interfertile, but yet have proteins diverged enough to be differentiated using mass spectrometry. Most of the protein-protein interactions are similar between hybrid and parents, and are consistent with the assembly of chimeric complexes, which we validated using an orthogonal approach for prefoldin complex. We also identify instances of altered protein-protein interactions in the hybrid, for instance in complexes related to proteostasis and in mitochondrial protein complexes. Overall, this study uncovers likely frequent occurrence of chimeric protein complexes with few exceptions, which may result from incompatibilities or imbalances between the parental proteomes.

Genomic instability in an interspecific hybrid of the genus Saccharomyces: a matter of adaptability

“…The genomes of S. cerevisiae and S. kudriavzevii are in general collinear and gene content is largely overlapping. Furthermore, the first indication of genetic compatibility has shown that macromolecular complexes between proteins from the different sub-genomes can be formed but at a very low frequency [73, 74], meaning that the two sub-genomes act largely as two separate entities. With these properties and with the fact that very little data is available for hybrids, S. cerevisiae makes a good proxy for the hybrids.…”

Proteotoxicity caused by perturbed protein complexes underlies hybrid incompatibility in yeast

“…Ultimately, some complex subunits may exhibit distinct evolutionary trajectories among different lineages, resulting in incompatibility when hybrids are formed 23 . This idea is corroborated by two studies that analyzed protein-protein interactions (PPIs) in protein complexes using the F1 hybrid diploids of different yeast species 62,63 . While many PPIs are conserved in hybrids, interactions involved in some biological functions related to proteostasis, metabolism, and mitochondria are specifically altered.…”