Acetylation dynamics and stoichiometry in Saccharomyces cerevisiae

Area of Science:

• Biochemistry
• Molecular Biology
• Yeast Genetics

Background:

• Lysine acetylation is a common posttranslational modification with largely unknown regulatory mechanisms.
• Understanding the dynamics and stoichiometry of acetylation is crucial for deciphering its biological roles.

Purpose of the Study:

• To investigate the dynamics and stoichiometry of lysine acetylation in Saccharomyces cerevisiae.
• To explore the relationship between acetyl-CoA generation, subcellular compartments, and acetylation levels.
• To identify proteins with high stoichiometry acetylation.

Main Methods:

• Quantitative mass spectrometry was employed to analyze acetylation in yeast.
• A novel method was developed to estimate acetylation stoichiometry.
• In vitro experiments assessed the nonenzymatic acetylation by acetyl-CoA.

Main Results:

• Acetylation levels accumulated in growth-arrested cells, dependent on compartmentalized acetyl-CoA generation.
• Mitochondrial acetylation correlated with acetyl-CoA concentration and showed higher basal levels than cytoplasmic acetylation.
• The majority of acetylation exhibited very low stoichiometry, except for histones, HAT/HDAC complexes, and transcription factors.

Conclusions:

• Most lysine acetylation in exponentially growing yeast occurs at low stoichiometry and is uniformly influenced by acetyl-CoA availability.
• Mitochondrial acetylation dynamics are distinct, with higher basal levels linked to localized acetyl-CoA concentration.
• High stoichiometry acetylation is enriched in key regulatory proteins like histones and transcription factors.