누에 배양세포 ( Bm5 ) 로부터 Protein Disulfide Isomerase 유전자 분리 및 특성 = Isolation and Characterization of a Gene Encoding a Protein Disulfide Isomerase from Bombyx mori Bm5 Cell Line

다국어 초록 (Multilingual Abstract)

Many secreted proteins have disulfide bonds that are important for their structure and function. Protein disulfide isomerase (PDI, EC 5.3.1.4.), an enzyme that catalyzes the formation and rearrangement of thiol/disulfide exchange reactions, is a resident of the endoplasmic reticulum (ER). The subcellular localization and its function as catalyst of disulfide bond formation in the biosynthesis of secretory and cell membrane proteins suggest that PDI plays a key role in the secretory pathway. To obtain genes related to molecular chaperone and the ER foldase from the Bombyx mori Bm5 cell line, the cDNA library was constructed with mRNA isolated from Bm5 cell line treated with by tunicamycin (5 ug/ml). We have isolated a cDNA encoding protein disulfide isomerase (bPDI), which consists of an open reading frame of 484 amino acids (55.6 kDa). It shows PDI-typical two active thioredoxin sites of CGHC and on ER retention signal of KDEL motif at its C-terminal. The bPDI protein shared less than 55% of the amino acid sequence motif at its C-terminal. The bPDI protein shared less than 55% of the amino acid sequence homology with other reported PDIs. bPDI is most genetically similar to the D. melanogaster PDI.