The phenotypephenotypes observed in aneuploid yeast strains—including cell cycle defects, increased glucose uptake, and sensitivity to protein productionprotein synthesis interference—are caused by the additional protein production from extra chromosome genes and the resulting imbalances in cellular protein composition. These phenotypes were only observed in strains carrying additional yeast genes, directly linking the phenotypic consequences to increased gene dosage rather than other aspects of aneuploidaneuploidy. [@torres_effects_2007]
Definitions
- aneuploidaneuploidy
- gene dosage
- protein production
- protein composition
- phenotypephenotypes
- cell cycle defects
- euploid
- glucose uptake
- phenotype
- protein productionprotein synthesis
- sensitivity
- aneuploid
Synthesis
Research across multiple aneuploid yeast systems has established that extra chromosomes lead to approximately twofold increases in the abundance of proteins encoded by genes on those duplicated chromosomes, creating an imbalanced protein composition that mechanistically underlies the shared phenotypic consequences of aneuploidy. This stoichiometric protein imbalance drives common fitness-related traits observed across different aneuploid strains regardless of which specific chromosome is gained, including impaired cell cycle progression, proliferative disadvantages, and increased glucose uptake. The heightened sensitivity of aneuploid cells to conditions that interfere with protein synthesis and protein folding further supports the model that proteotoxic stress from imbalanced protein stoichiometry represents a general mechanism by which gene dosage changes produce aneuploid phenotypes. While the general principle of protein imbalance causing aneuploid phenotypes appears well-supported, the specific molecular pathways through which stoichiometric disruption manifests as particular cellular defects, and whether context-dependent effects of specific duplicated genes can override or modulate these general consequences, remain areas requiring further investigation.
Related
- Mps1 truncation-induced CIN generates convergent recurrent chromosome gains
- Aneuploidy alters cellular protein composition approximately twofold
- Different aneuploid cells share common fitness-related traits
- Aneuploidy impairs cell cycle progression in haploid yeast
- Aneuploidy heightens sensitivity to protein synthesis interference
- Aneuploidy increases glucose uptake in yeast cells
- Aneuploidy exhibits dual roles as oncogenic and tumor-suppressive
- Aneuploidy causes proliferative disadvantage independent of extra chromosome identity