Arrest-defective protein 1 (ARD1), first identified in yeast,
apexbio the catalytic subunit of NatA acetyltransferase, responsible for N-terminal α-acetylation [1]. Mutation of Ard1 in yeast leads to defective entry into the stationary phase and sporulation in response to nutrient deprivation or mating pheromone α-factor [2] and [3]. In mammalian cells, ARD1 possesses both N-terminal α-protein and ε-protein acetylation activities, thus representing a novel kind of acetyltransferase [4] and [5]. ARD1 has been reported to mediate hypoxia-inducible factor 1α (HIF-1α) ubiquitination and degradation through Lys532 acetylation [5]; however, several groups were unable to replicate this observation [6], [7] and [8]. Another ε-acetylation substrate of ARD1 is β-catenin, which was shown to mediate the cell proliferation effect of ARD1 in lung cancer
cells [9]. In addition to cell growth control, ARD1 is also involved in DNA damage-induced apoptosis [10]. Although ARD1 plays a critical role in regulating cell proliferation and apoptosis, the molecular mechanisms regulating ARD1 stability and functions remain largely unclear.
