Abstract
Cellular transcriptional activator sequences from a Syrian hamster cell line (baby hamster kidney (BHK] were rescued by a double selection procedure. An enhancer-deficient SV40 promoter was linked to the neomycin resistance (NEO) gene and transfected into BHK cells. Genomic DNA fragments of G418-resistant cell clones containing multiple copies of integrated plasmid DNAs were used for a second transfection of BHK cells, resulting in the genomic integration of a single copy plasmid which expresses the NEO gene efficiently. For rapid cloning of the integrated promoter and adjacent cellular DNA sequences, these cell clones were fused to COS-1 cells, thereby providing SV40 large T antigen and the monkey cell permissive factor necessary for SV40 replication. Resulting from this fusion, the integrated plasmid and adjacent sequences were amplified to about 1000 extrachromosomal copies giving rise to an abundant pool of promoter elements which thus can be cloned into a plasmid very easily for further investigations. Promoter analyses of three clones in the chloramphenicol acetyltransferase transient expression assay demonstrated that the recombination with cellular DNA enables the initially defective SV40 promoter to express at wild type levels.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
