AROS is a family of chordate proteins active in the nucleolus. It has a stretch of polylysines at the N-terminus and in the middle regions and it localises to the nucleus and especially the nucleolus in high concentrations. It binds to the 40S ribosomal protein RPS19, which is implicated in erythropoiesis [1]. AROS is an active regulator of Sirtuin (SIRT1), an NAD+-dependent deacetylase protein that plays a role in cell survival and hormonal signalling, and AROS regulates the activity of SIRT1 by enhancing SIRT1-mediated de-acetylation of p53 and thus regulates growth of the cell [2].

1: A novel nucleolar protein interacts with ribosomal protein S19. Maeda N, Toku S, Kenmochi N, Tanaka T; Biochem Biophys Res Commun. 2006;339:41-46. PMID:16289379

2: Active regulator of SIRT1 cooperates with SIRT1 and facilitates suppression of p53 activity. Kim EJ, Kho JH, Kang MR, Um SJ; Mol Cell. 2007;28:277-290. PMID:17964266