The correlation between increased protein abundance and gene dosage in aneuploid yeast becomes apparent when log2 ratios of protein levels are sorted by the chromosomal position of their encoding genes. Proteins encoded on duplicated chromosomes show consistent elevation relative to those on non-duplicated chromosomes, demonstrating a direct relationship between gene copy number and protein abundance. [@dephoure_quantitative_2014]
Definitions
- protein abundance
- gene dosage
- chromosomal position
- log2 ratios
- duplicated chromosomes
- aneuploid yeast
- copy number
Synthesis
Quantitative proteomics studies using SILAC and mass spectrometry in aneuploid yeast strains have established that protein abundance changes scale directly with chromosomal copy number, demonstrating that proteins encoded on duplicated chromosomes consistently increase approximately twofold in abundance compared to wild-type cells. This proportional relationship between gene dosage and protein stoichiometry has been observed across all examined disomic strains, with measurable log2 ratios correlating with chromosomal position, indicating that protein levels track the physical location of genes on duplicated chromosomes. The mechanistic basis for this high-fidelity response appears to be a direct, largely uncompensated translation of increased gene copy number into proportional protein output, creating systematic imbalances in cellular protein composition. While the correlation between chromosomal position and protein abundance is well-established, the related concept notes do not address whether any compensatory mechanisms or regulatory feedbacks might modulate this response for specific protein classes or functional categories.
Related
- Quantitative proteomics measures 70-80% of yeast open reading frames
- Aneuploidy alters cellular protein composition approximately twofold