Molecular Characterization of Trehalose-6-Phosphate Synthetase 2 in Nosema bombycis

Pebrine caused by Nosema bombycis infection is one of the most threatening diseases to sericulture. Trehalose-6-phosphate synthetase is a key rate-limiting enzyme in the trehalose metabolism pathway. N. bombycis trehalose phosphate synthetase 2 (NbTPS2) is a subcellular unit of N. bombycis trehalose synthase gene complex. Here, NbTPS2 gene was amplified, sequenced and expressed in E. coli BL21 strain. The result showed that NbTPS2 gene contains an open reading frame with length of 1371 bp and encoded a protein with molecular mass of approximately 57.87 kDa. His pull-down result showed that 66 N. bombycis proteins and 359 silkworm proteins may be directly or indirectly interacted with NbTPS2. Molecular phylogeny analysis result showed that NbTPS2 gene was conservative in different microsporidia. In addition, the highest relative transcription level of NbTPS2 at 6 h after infection suggesting that NbTPS2 plays an important role in the early infection stage (possibly germination stage) for N. bombycis. These results revealed the molecular characteristic of NbTPS2, laying the molecular foundation for the subsequent functional study of NbTPS2.