Fluorescence in situ hybridization and chromosomal organization of the sirtuin 4 gene (Sirt4) in the mouse.

The sirtuins (SIRT1-7), also being referred to as class III HDACs, exert NAD-dependent deacetylase and/or ADP-ribosyltransferase activities in various cellular compartments including the cell nucleus, the cytoplasm and the mitochondria. The sirtuins play a central role in epigenetic gene silencing, DNA repair and recombination, cell-cycle, microtubule organization, and in the regulation of aging. SIRT4 is a mitochondrial protein that lacks deacetylase activities but efficiently works as an ADP-ribosyltransferase. We have isolated and characterized the murine Sirt4 genomic sequence, which spans a region of 12kb and which has one single genomic locus. Determination of the exon-intron splice junctions established that SIRT4 is encoded by 6 exons. The 1648bp murine Sirt4 transcript encodes a 418 aa protein with a predictive molecular weight of 47.3kDa. Fluorescence in situ hybridization analysis identified a single genomic locus for murine Sirt4 gene on chromosome 5F and is neighbored by the PLA2G1B and PXN genes.