Humanization of yeast genes with multiple human orthologs reveals functional divergence between paralogs.
Level 5 - mechanism / opinion, no new human data
Bench and model organism research with no direct human clinical data.
PubMed 32421706 · doi:10.1371/journal.pbio.3000627
What was done
The authors systematically tested whether human orthologs from duplicated gene families (1:2 and 1:>2 yeast-to-human gene ratios) could functionally complement essential yeast genes in Saccharomyces cerevisiae. They conducted over 400 replaceability assays and assessed whether sequence divergence, human tissue expression patterns, protein-protein interaction networks, subcellular localization, and in silico evolutionary simulations predicted functional rescue.
What was found
Out of >400 replaceability assays, 50 new human-yeast complementation pairs were identified. In 1:2 ortholog families, the human paralog that successfully replaced the yeast gene was consistently the one with lower sequence divergence and broader tissue expression across human tissues. For 1:>2 ortholog expansions, functional replaceability correlated with retention of ancestral subcellular localization and conserved functional network interactions. Replaceability by all members of a human gene family was rarely observed. Specific statistical metrics and exact effect sizes were not reported in the abstract.
Why it matters
This work provides empirical rules for functional divergence among duplicated human paralogs and establishes 50 new validated humanized yeast models to functionally dissect human genes in a simplified genetic context.
Limits
The abstract reports no exact numerical proportions, confidence intervals, or p-values for the predictive features. Assays in single-celled yeast cannot capture complex mammalian phenotypes, developmental requirements, or tissue-specific regulatory contexts.
Cited by
- context Approximately 70% of genes found in yeast share functional homologs in humans.