Molecular identification and functional characterization of the first Nα‐acetyltransferase in plastids by global acetylome profiling. Issue 14 (18th June 2015)

• Record Type: Journal Article
• Authors: Dinh, Trinh V.; Bienvenut, Willy V.; Linster, Eric; Feldman‐Salit, Anna; Jung, Vincent A.; Meinnel, Thierry; Hell, Rüdiger; Giglione, Carmela; Wirtz, Markus; Van Damme, Petra; Gevaert, Kris
• Is Part Of: Proteomics. Volume 15:Issue 14(2015:Jul.)
• Page Start: 2426
• Page End: 2435
• Publication Date: 2015-06-18
• Subjects: Proteins -- Separation -- Periodicals; Bioinformatics -- Periodicals; Proteomics -- Periodicals; Genomes -- Periodicals; Molecular genetics -- Periodicals; 572.605
• DOI: 10.1002/pmic.201500025
• Languages: English
• ISSNs: 1615-9853

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Protein N<sup>α</sup>‐terminal acetylation represents one of the most abundant protein modifications of higher eukaryotes. In humans, six N<sup>α</sup>‐acetyltransferases (Nats) are responsible for the acetylation of approximately 80% of the cytosolic proteins. N‐terminal protein acetylation has not been evidenced in organelles of metazoans, but in higher plants is a widespread modification not only in the cytosol but also in the chloroplast. In this study, we identify and characterize the first organellar‐localized Nat in eukaryotes. A primary sequence‐based search in <italic>Arabidopsis thaliana</italic> revealed seven putatively plastid‐localized Nats of which AT2G39000 (AtNAA70) showed the highest conservation of the acetyl‐CoA binding pocket. The chloroplastic localization of AtNAA70 was demonstrated by transient expression of AtNAA70:YFP in Arabidopsis mesophyll protoplasts. Homology modeling uncovered a significant conservation of tertiary structural elements between human HsNAA50 and AtNAA70. The in vivo acetylation activity of AtNAA70 was demonstrated on a number of distinct protein N<sup>α</sup>‐termini with a newly established global acetylome profiling test after expression of AtNAA70 in <italic>E. coli</italic>. AtNAA70 predominately acetylated proteins starting with M, A, S and T, providing an explanation for most protein N‐termini acetylation events found in chloroplasts. Like HsNAA50, AtNAA70 displays N<sup>ε</sup>‐acetyltransferase activity on three internal lysine residues. All MS data have been deposited in the ProteomeXchange with identifier PXD001947 (<ext-link ext-link-type="uri" xlink:href="http://proteomecentral.proteomexchange.org/dataset/PXD001947" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">http://proteomecentral.proteomexchange.org/dataset/PXD001947</ext-link>).</p> </abstract>