A Saccharomyces cerevisiae model reveals in vivo functional impairment of the Ogden syndrome N-terminal acetyltransferase NAA10 Ser37Pro mutant.

Abstract

N-terminal acetylation (Nt-acetylation) occurs on the majority of eukaryotic proteins and is catalyzed by N-terminal acetyltransferases (NATs). Nt-acetylation is increasingly recognized as a vital modification with functional implications ranging from protein degradation to protein localization. Although early genetic studies in yeast demonstrated that NAT-deletion strains displayed a variety of phenotypes, only recently, the first human genetic disorder caused by a mutation in a NAT gene was reported; boys diagnosed with the X-linked Ogden syndrome harbor a p.Ser37Pro (S37P) mutation in the gene encoding Naa10, the catalytic subunit of the NatA complex, and suffer from global developmental delays and lethality during infancy. Here, we describe a Saccharomyces cerevisiae model developed by introducing the human wild-type or mutant NatA complex into yeast lacking NatA (NatA-Δ). The wild-type human NatA complex phenotypically complemented the NatA-Δ strain, whereas only a partial rescue was observed for the Ogden mutant NatA complex suggesting that hNaa10 S37P is only partially functional in vivo. Immunoprecipitation experiments revealed a reduced subunit complexation for the mutant hNatA S37P next to a reduced in vitro catalytic activity. We performed quantitative Nt-acetylome analyses on a control yeast strain (yNatA), a yeast NatA deletion strain (yNatA-Δ), a yeast NatA deletion strain expressing wild-type human NatA (hNatA), and a yeast NatA deletion strain expressing mutant human NatA (hNatA S37P). Interestingly, a generally reduced degree of Nt-acetylation was observed among a large group of NatA substrates in the yeast expressing mutant hNatA as compared with yeast expressing wild-type hNatA. Combined, these data provide strong support for the functional impairment of hNaa10 S37P in vivo and suggest that reduced Nt-acetylation of one or more target substrates contributes to the pathogenesis of the Ogden syndrome. Comparative analysis between human and yeast NatA also provided new insights into the co-evolution of the NatA complexes and their substrates. For instance, (Met-)Ala- N termini are more prevalent in the human proteome as compared with the yeast proteome, and hNatA displays a preference toward these N termini as compared with yNatA.

• Authors: Petra Van Damme, Svein I Støve, Nina Glomnes, Kris Gevaert, Thomas Arnesen
• Journal: Molecular & cellular proteomics : MCP (Mol Cell Proteomics) Vol. 13 Issue 8 Pg. 2031-41 (Aug 2014) ISSN: 1535-9484 [Electronic] United States
• PMID: 24408909 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Chemical References

• Saccharomyces cerevisiae Proteins
• Serine
• Proline
• N-Terminal Acetyltransferase A
• NAA10 protein, human
• N-Terminal Acetyltransferase E
• N-Terminal Acetyltransferases

Topics

• Acetylation
• Amino Acid Substitution
• Humans
• N-Terminal Acetyltransferase A (genetics, metabolism)
• N-Terminal Acetyltransferase E (genetics, metabolism)
• N-Terminal Acetyltransferases (genetics, metabolism)
• Phenotype
• Proline (metabolism)
• Saccharomyces cerevisiae (genetics, growth & development)
• Saccharomyces cerevisiae Proteins (genetics, metabolism)
• Serine (metabolism)
• Species Specificity