N-alpha terminal acetylation is one of the major protein modifications in eukaryotes carried out by distinct Nats (N-alpha acetyltransferases). The core NatA complex is composed of the catalytic NAA10 and the auxiliary NAA15 subunit and co-translationally acetylates majority of the cytosolic proteins. HYPK interacts with NatA core complex in human and fungus in vivo and in vitro, regulating its activity. Here, a mass spectrometry approach was applied to quantify the steady-state levels of the core NatA subunits, NAA10 and NAA15 and of HYPK in the roots of Arabidopsis mutants carrying a T-DNA insertion in the HYPK gene (AT3G06610).