Molecular identification and functional characterization of the first Nα-acetyltransferase in plastids by global acetylome profiling
Protein Nα-terminal acetylation represents one of the most abundant protein modifications of higher eukaryotes. In humans, six Nα-acetyltransferases (Nats) are responsible for the acetylation of approximately 80% of the cytosolic proteins. N-terminal protein acetylation has not been evidenced in org...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
April 30, 2015
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| In: |
Proteomics
Year: 2015, Volume: 15, Issue: 14, Pages: 2426-2435 |
| ISSN: | 1615-9861 |
| DOI: | 10.1002/pmic.201500025 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1002/pmic.201500025 Verlag, Volltext: http://onlinelibrary.wiley.com/doi/10.1002/pmic.201500025/abstract 
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| Author Notes: | Trinh V. Dinh, Willy V. Bienvenut, Eric Linster, Anna Feldman-Salit, Vincent A. Jung, Thierry Meinnel, Rüdiger Hell, Carmela Giglione and Markus Wirtz |
| Summary: | Protein Nα-terminal acetylation represents one of the most abundant protein modifications of higher eukaryotes. In humans, six Nα-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 Arabidopsis thaliana 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 Nα-termini with a newly established global acetylome profiling test after expression of AtNAA70 in E. coli. 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 Nε-acetyltransferase activity on three internal lysine residues. All MS data have been deposited in the ProteomeXchange with identifier PXD001947 (http://proteomecentral.proteomexchange.org/dataset/PXD001947). |
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| Item Description: | Gesehen am 19.05.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1615-9861 |
| DOI: | 10.1002/pmic.201500025 |