Sequence of a cDNA that specifies the uridine diphosphate N-acetyl-D-glucosamine:dolichol phosphate N-acetylglucosamine-1-phosphate transferase from Chinese hamster ovary cells

We have isolated a portion of the uridine diphosphate N-acetyl-D-glucosamine:dolichol phosphate N-acetylglucosamine-1-phosphate transferase gene (GTR2) from the genome of a tunicamycin-resistant clonal Chinese hamster ovary cell line, 3E11. The genomic fragment was selected by its hybridization to the yeast ALG-7 gene at low stringency. A 2.46-kilobase cDNA was isolated from a library prepared from 3E11 mRNA and probed with GTR2. The cDNA contained an open reading frame that encodes a protein of 408 amino acids with a molecular mass of 44.9 kDa. This protein was 43% identical in amino acid sequence to the protein of 448 amino acids encoded by the ALG-7 gene. The GTR2 gene fragment contained sequences for four exons coding for the carboxyl-terminal half of the protein. Transferase DNA sequences in 3E11 cells were 12-fold elevated over wild-type cells and 25-fold elevated when 3E11 cells were grown in the presence of tunicamycin. Transferase RNA levels in 3E11 cells were also elevated over wild-type levels but appeared unchanged by the presence of tunicamycin in the medium.