Special Issue: "Yeast as a Model System to Study Human Diseases"

Yeast is a well-known eukaryote that has been fundamental in the discovery of principles governing cellular life. Despite its phylogenetic distance from humans, budding yeast shares more than 2000 genes (approximately 30% of its genome) with humans [1]. In addition, 45% of its genome is replaceable with a human gene [2]. Studies on Saccharomyces cerevisiae have led to the discovery of key regulators of the cell cycle, mechanisms by which chromosomes are protected by telomeres and the enzyme telomerase, and processes that control autophagy [3]. Yeast has been instrumental in understanding how protein misfolding can lead to neurodegenerative diseases and how mutations in mismatch repair genes, such as MSH2 and MLH1, can cause hereditary non-polyposis colorectal cancer [4]. Furthermore, yeast models have proven valuable for drug screening and the functional characterization of disease-associated genes identified through human genomics [5]. Taken together, this body of evidence supports the use of yeast as a robust system to elucidate the function of many human genes. However, the emergence of CRISPR/Cas9 technology has significantly facilitated genome editing in human cells and animal models, raising a critical question for yeast researchers: Can yeast remain a valid model system for biomedical studies? This Special Issue clearly demonstrates that yeast continues to be a powerful model organism, offering valuable tools for both fundamental and applied biological research. The collected papers illustrate recent advances across various fields of cellular biology, each addressing important unresolved questions. We have grouped the contributions into three thematic sections: (1) Functional implications of human genetic variants; (2) Yeast as a sensing and screening/predictive platform for biomedical applications and drug discovery; and (3) Yeast models to unravel protein misfolding, neurodegeneration, and host–pathogen interactions.