Human NAA30 can rescue yeast mak3∆ mutant growth phenotypes

Area of Science:

• Biochemistry and Molecular Biology
• Proteomics
• Cellular Biology

Background:

• N-terminal acetylation is a key co-translational protein modification catalyzed by N-terminal acetyltransferases (NATs).
• The NatC complex, comprising NAA30, NAA35, and NAA38, is a major NAT enzyme acetylating approximately 20% of the proteome.
• NatC activity is essential for substrate translocation to the Golgi, inner nuclear membrane localization, and mitochondrial function.

Purpose of the Study:

• To investigate the functional significance of the NatC complex, specifically the MAK3/NAA30 subunit, in yeast.
• To establish an efficient method for analyzing subtle growth defects associated with NAT enzyme activity.
• To assess the evolutionary conservation of MAK3/NAA30 function and its potential in human NAA30 research.

Main Methods:

• Comparative viability and growth assays in yeast strains lacking MAK3/NAA30.
• Utilized two distinct experimental approaches and two yeast strains to validate findings.
• Employed liquid growth assays for analyzing subtle growth defects under various stress conditions.

Main Results:

• Yeast cells lacking MAK3/NAA30 exhibit poor growth on non-fermentable carbon sources and under other stress conditions.
• Liquid growth assays were identified as the optimal method for minimizing information loss in growth defect analysis.
• Human NAA30 can functionally substitute for yeast MAK3/NAA30, contingent on the yeast strain's genetic background.

Conclusions:

• The function of MAK3/NAA30 is evolutionarily conserved between yeast and humans.
• The characterized yeast system, utilizing high-throughput liquid growth assays, offers a robust platform for studying human NAA30 variants.
• This research highlights the importance of NatC complex activity for cellular homeostasis and provides a valuable tool for future studies.