An Organellar N alpha-Acetyltransferase, Naa60, Acetylates Cytosolic N Termini of Transmembrane Proteins and Maintains Golgi Integrity

作者：Aksnes Henriette; Van Damme Petra; Goris Marianne; Starheim Kristian K; Marie Michael; Stove Svein Isungset; Hoel Camilla; Kalvik Thomas Vikestad; Hole Kristine; Glomnes Nina; Furnes Clemens; Ljostveit Sonja; Ziegler Mathias; Niere Marc; Gevaert Kris; Arnesen Thomas^*

来源：Cell Reports, 2015, 10(8): 1362-1374.

DOI：10.1016/j.celrep.2015.01.053

N-terminal acetylation is a major and vital protein modification catalyzed by N-terminal acetyltransferases (NATs). NatF, or N alpha-acetyltransferase 60 (Naa60), was recently identified as a NAT in multicellular eukaryotes. Here, we find that Naa60 differs from all other known NATs by its Golgi localization. A new membrane topology assay named PROMPT and a selective membrane permeabilization assay established that Naa60 faces the cytosolic side of intracellular membranes. An Nt-acetylome analysis of NAA60-knockdown cells revealed that Naa60, as opposed to other NATs, specifically acetylates transmembrane proteins and has a preference for N termini facing the cytosol. Moreover, NAA60 knockdown causes Golgi fragmentation, indicating an important role in the maintenance of the Golgi's structural integrity. This work identifies a NAT associated with membranous compartments and establishes N-terminal acetylation as a common modification among transmembrane proteins, a thus-far poorly characterized part of the N-terminal acetylome.

• 出版日期2015-3-3