Clone of N-terminal acetylation

Background

N-terminal acetylation (NTA) is a pervasive protein modification in higher eukaryotes but rarely occurs in prokaryotes. NTA is catalyzed by ribosome-tethered N-acetyltransferase (Nat) complexes consisting of a catalytically active and one or more auxiliary subunits (see figure). Because of its co-translational nature and the absence of deacetylases, NTA was supposed to be static and unregulated in eukaryotes. When this project started, the plant N-terminal protein acetylation machinery was barely characterized, and the impact of NTA on protein fate in plants was unknown.

N-terminal protein acetylation machinery in eukaryotes

Research Highlights

2021 In collaboration with the team of Prof. Felix Willmund (University of Kaiserlautern), we provided evidence for a ribosome-tethered N-acetyltransferase in plastids. 

2020 We characterized the NAA50 homolog in plants and uncovered its crucial function for development and regulation of stress responses.

2020 We show that acetylation of protein N-termini by NatB affects plant growth and the immunity towards pathogens.

2020 We identified the plant NAA60 homolog as a plasma membrane-anchored Nat that is required for a successful response towards protein harming stresses. NAA60 has a broad substrate specificity in vitro and acetylates membrane-associated proteins in planta.

2015 to 2020 We identified the first plastid-localized N-acetyltransferase and contributed in the framework of the ERA-CAPS consortium Kat/Nat to the characterization of the dual active protein acetyltransferase machinery in plastids.

2015 We identified the NatA complex in the reference plant Arabidopsis thaliana and showed that this essential protein complex addresses approximately 40 % of the proteome. The phytohormone ABA down-regulates the abundance of the core NatA subunits, NAA10 and NAA15, which enhances drought tolerance by triggering stomata closure.