Retention of protein complex membership by ancient duplicated gene products in budding yeast

To investigate functional divergence of gene duplicates, we examined the protein–protein interactions and coexistence in complexes of paralogs resulting from an ancient whole-genome duplication in yeast. Strikingly, half the surveyed paralog pairs were found to be co-clustered in protein complexes, and were more conserved and highly expressed than non-co-clustered paralogs; however, their discordant expression patterns and conservation rates indicate differential regulation of subfunctionalized paralogs. These results highlight the value of protein complex membership in studying functional divergence among gene duplicates.