Co-translational, Post-translational, and Non-catalytic Roles of N-Terminal Acetyltransferases.

Summary Recent studies of N-terminal acetylation have identified new N-terminal acetyltransferases (NATs) and expanded the known functions of these enzymes beyond their roles as ribosome-associated co-translational modifiers. For instance, the identification of Golgi- and chloroplast-associated NATs shows that acetylation of N termini also happens post-translationally. In addition, we now appreciate that some NATs are highly specific; for example, a dedicated NAT responsible for post-translational N-terminal acetylation of actin was recently revealed. Other studies have extended NAT function beyond Nt acetylation, including functions as lysine acetyltransferases (KATs) and non-catalytic roles. Finally, emerging studies emphasize the physiological relevance of N-terminal acetylation, including roles in calorie-restriction-induced longevity and pathological α-synuclein aggregation in Parkinson's disease. Combined, the NATs rise as multifunctional proteins, and N-terminal acetylation is gaining recognition as a major cellular regulator. N-terminal acetylation, long considered a co-translational and static modification, recently stepped into the post-translational world, and several reports now suggest regulation and crosstalk with other modifications as well as moonlighting functions. Aksnes et al. review novel functions of N-terminal acetyltransferases, including the most recently described Nt acetylation of actin. [ABSTRACT FROM AUTHOR]