Cell-specific effects of human cytomegalovirus unique region on recombinant protein expression.
The major immediate-early (MIE) promoter of human cytomegalovirus (CMV) is widely used to express recombinant proteins in mammalian cells. CMV MIE promoter contains a strong enhancer and an AT-rich unique region (UR). The UR can function as an insulator or a negative element of CMV MIE promoter, depending on the cellular proteins associated with it. To examine the effects of UR on recombinant protein expression in mammalian cells, we constructed two CMV MIE promoter-based expression plasmids for comparison to the conventional CMV MIE promoter by removing or adding UR. Addition of UR enhances transgene expression in HEK293 stable cells while removal of UR increases both transient and stably integrated expression in HeLa cells. Our results further demonstrate that the cell-specific effect of UR depends on the protein levels of UR-binding proteins, pancreatic-duodenal homeobox factor-1, special AT-rich sequence binding protein 1, and CCAAT displacement protein, in these cells. Collectively, these modified CMV expression plasmids can be utilized to improve recombinant protein production in specific mammalian cell lines.
Lee
Jialing
J
Expression Engineering Group, Bioprocessing Technology Institute, 20 Biopolis Way, #06-01 Centros, Singapore, 138668, Singapore.
Lau
Joanne
J
Chong
Grace
G
Chao
Sheng-Hao
SH
D000818:Animals; D016466:CHO Cells; D002457:Cell Extracts; D002467:Cell Nucleus / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D003587:Cytomegalovirus / Q000235:genetics*; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D036961:Matrix Attachment Region Binding Proteins / Q000378:metabolism; D008954:Models, Biological; D009928:Organ Specificity; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism; D014162:Transfection
D002457:Cell Extracts; D018398:Homeodomain Proteins; D036961:Matrix Attachment Region Binding Proteins; D011994:Recombinant Proteins; C076189:SATB1 protein, human; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein