Cloning and Characterization of NAD-dependent Deacetylase Sirtuin 2 Homolog from the Silkworm, Bombyx mori.

Sirtuin2 (Sirt2) is a kind of NAD+-dependent deacetylases ranging from bacteria to human and play an important role in many biological processes especially in lifespan. We performed genome analysis and protein prediction of Sirt2 of B. mori (BmSirt2). The cDNA sequence of BmSirt2 contains an ORF of 1164 bp encoding 387 amino acid residues with a predicted molecular mass and isoelectric point of 43.37 kDa and 5.02, respectively. This protein shows high degrees of identity with other species. Phylogenetic relationship analysis showed that the BmSirt2 protein was in the same subgroup as the Sirt2 from invertebrate animals. RT-PCR analysis of gene expression in multiple tissues showed that Sirt2 gene was widely expressed in B. mori. BmSirt2 was successfully expressed in E. coli with a molecular mass of 48.0 kDa. The identification of the recombinant protein by MALDI-TOF-MS and western blotting showed this fusion protein was the correct one.