NatB-mediated N-terminal acetylation affects growth and biotic stress responses

• Verfasst von: Huber, Monika [VerfasserIn]
• Verfasst von: Bienvenut, Willy V. [VerfasserIn]
• Verfasst von: Linster, Eric [VerfasserIn]
• Verfasst von: Stephan, Iwona [VerfasserIn]
• Verfasst von: Armbruster, Laura [VerfasserIn]
• Verfasst von: Sticht, Carsten [VerfasserIn]
• Verfasst von: Layer, Dominik Christian [VerfasserIn]
• Verfasst von: Lapouge, Karine [VerfasserIn]
• Verfasst von: Meinnel, Thierry [VerfasserIn]
• Verfasst von: Sinning, Irmgard [VerfasserIn]
• Verfasst von: Giglione, Carmela [VerfasserIn]
• Verfasst von: Hell, Rüdiger [VerfasserIn]
• Verfasst von: Wirtz, Markus [VerfasserIn]
• Titel: NatB-mediated N-terminal acetylation affects growth and biotic stress responses
• Verf.angabe: Monika Huber, Willy V. Bienvenut, Eric Linster, Iwona Stephan, Laura Armbruster, Carsten Sticht, Dominik Layer, Karine Lapouge, Thierry Meinnel, Irmgard Sinning, Carmela Giglione, Ruediger Hell, Markus Wirtz
• E-Jahr: 2020
• Jahr: [February 2020]
• Umfang: 15 S.
• Fussnoten: Gesehen am 30.03.2020
• Titel Quelle: Enthalten in: Plant physiology
• Ort Quelle: Oxford : Oxford University Press, 1926
• Jahr Quelle: 2020
• Band/Heft Quelle: 182(2020), 2, Seite 792-806
• ISSN Quelle: 1532-2548
• DOI: doi:10.1104/pp.19.00792
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1693467739

Abstract

N∝-terminal acetylation (NTA) is one of the most abundant protein modifications in eukaryotes. In humans, NTA is catalyzed by seven Nα-acetyltransferases (NatA-F and NatH). Remarkably, the plant Nat machinery and its biological relevance remain poorly understood, although NTA has gained recognition as a key regulator of crucial processes such as protein turnover, protein-protein interaction, and protein targeting. In this study, we combined in vitro assays, reverse genetics, quantitative N-terminomics, transcriptomics, and physiological assays to characterize the Arabidopsis (Arabidopsis thaliana) NatB complex. We show that the plant NatB catalytic (NAA20) and auxiliary subunit (NAA25) form a stable heterodimeric complex that accepts canonical NatB-type substrates in vitro. In planta, NatB complex formation was essential for enzymatic activity. Depletion of NatB subunits to 30% of the wild-type level in three Arabidopsis T-DNA insertion mutants (naa20-1, naa20-2, and naa25-1) caused a 50% decrease in plant growth. A complementation approach revealed functional conservation between plant and human catalytic NatB subunits, whereas yeast NAA20 failed to complement naa20-1. Quantitative N-terminomics of approximately 1000 peptides identified 32 bona fide substrates of the plant NatB complex. In vivo, NatB was seen to preferentially acetylate N termini starting with the initiator Met followed by acidic amino acids and contributed 20% of the acetylation marks in the detected plant proteome. Global transcriptome and proteome analyses of NatB-depleted mutants suggested a function of NatB in multiple stress responses. Indeed, loss of NatB function, but not NatA, increased plant sensitivity toward osmotic and high-salt stress, indicating that NatB is required for tolerance of these abiotic stressors.