Onyango Patrick, Celic Ivana, McCaffery J Michael, Boeke Jef D, Feinberg Andrew P
Institute of Genetic Medicine, Department of Medicine, The Johns Hopkins University School of Medicine, 1064 Ross, 720 Rutland Avenue, Baltimore, MD 21205, USA.
Proc Natl Acad Sci U S A. 2002 Oct 15;99(21):13653-8. doi: 10.1073/pnas.222538099. Epub 2002 Oct 8.
The SIR2 (silent information regulator 2) gene family has diverse functions in yeast including gene silencing, DNA repair, cell-cycle progression, and chromosome fidelity in meiosis and aging. Human homologues, termed sirtuins, are highly conserved but are of unknown function. We previously identified a large imprinted gene domain on 11p15.5 and investigated the 11p15.5 sirtuin SIRT3. Although this gene was not imprinted, we found that it is localized to mitochondria, with a mitochondrial targeting signal within a unique N-terminal peptide sequence. The encoded protein was found also to possess NAD(+)-dependent histone deacetylase activity. These results suggest a previously unrecognized organelle for sirtuin function and that the role of SIRT3 in mitochondria involves protein deacetylation.
SIR2(沉默信息调节因子2)基因家族在酵母中具有多种功能,包括基因沉默、DNA修复、细胞周期进程以及减数分裂和衰老过程中的染色体保真度。其人类同源物称为沉默调节蛋白,高度保守但功能未知。我们之前在11p15.5上鉴定出一个大的印记基因结构域,并对11p15.5沉默调节蛋白SIRT3进行了研究。尽管该基因没有印记,但我们发现它定位于线粒体,在一个独特的N端肽序列内有一个线粒体靶向信号。还发现编码的蛋白质具有NAD(+)依赖性组蛋白脱乙酰酶活性。这些结果表明沉默调节蛋白功能存在一个以前未被认识的细胞器,并且SIRT3在线粒体中的作用涉及蛋白质去乙酰化。