CMV promoter

The human cytomegalovirus immediate-early (CMV) promoter is typically not repressed in 293 cells due to the presence of the adenovirus E1a gene. It contains a cryptic Escherichia coli promoter, when the gene of interest is in the correct orientation for eukaryotic expression, this cryptic E. coli promoter will often express the gene in E. coli. The CMV promoter works in S. pombe, but is essentially non-functional in S. cerevisiae. The CMV promoter has a broad host range that includes a wide variety of mouse tissue and cell types and several human cell lines including B-lymphoblastoma, a lung cancer cell line, embryonic kidney cells, breast cancer cell lines and placenta cells. Expression using CMV promoter-based vectors has also been observed in a canine thymus cell line, Xenopus oocytes, quail embryo fibroblasts and avian bursal lymphomas, D. melanogaster (insect) cells and yeast. The CMV promoter does not seem to work in T24 and HCV29 human bladder urethelium carcinoma cell lines but SV40 (part no. GA-pro-00020.1) exhibits high activity in these cell lines. Both T24 and HCV29 cell lines originated from human transitional cell carcinoma of bladder urethelium.The CMV promoter is weak in B cells.