title: 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.affiliation: From the ‡Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium; §Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium; Petra.vandamme@vib-ugent.be thomas.arnesen@mbi.uib.no.
authors.forename: Petra
authors.initials: P
authors.lastname: Van Damme
authors.affiliation: ¶Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway; **Department of Surgery, Haukeland University Hospital, N-5021 Bergen, Norway.
authors.forename: Svein I
authors.initials: SI
authors.lastname: Støve
authors.affiliation: ¶Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway; ‖Department of Clinical Science, University of Bergen, N-5020 Bergen, Norway; and.
authors.forename: Nina
authors.initials: N
authors.lastname: Glomnes
authors.affiliation: From the ‡Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium; §Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium;
authors.forename: Kris
authors.initials: K
authors.lastname: Gevaert
authors.affiliation: ¶Department of Molecular Biology, University of Bergen, N-5020 Bergen, Norway; **Department of Surgery, Haukeland University Hospital, N-5021 Bergen, Norway Petra.vandamme@vib-ugent.be thomas.arnesen@mbi.uib.no.
authors.forename: Thomas
authors.initials: T
authors.lastname: Arnesen
mesh_terms: D000107:Acetylation; D019943:Amino Acid Substitution; D006801:Humans; D063209:N-Terminal Acetyltransferase A / Q000235:genetics / Q000378:metabolism*; D063213:N-Terminal Acetyltransferase E / Q000235:genetics / Q000378:metabolism*; D063206:N-Terminal Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011392:Proline / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D013045:Species Specificity
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D012694:Serine; D011392:Proline; D063209:N-Terminal Acetyltransferase A; C504824:NAA10 protein, human; D063213:N-Terminal Acetyltransferase E; D063206:N-Terminal Acetyltransferases