Related Experiment Videos
Endogenous and exogenous pituitary-specific promoters are differentially controlled
P J Hippenmeyer1, A M Rankin, B A Reitz
1G.D. Searle and Company, Research and Development, St. Louis, MO 63198, USA.
Molecular and Cellular Endocrinology
|February 1, 1995
Summary
Reporter gene expression in engineered GH3 cells showed low protein production, despite high endogenous hormone levels. Pit-1 transactivator enhanced prolactin promoter activity but not growth hormone promoter activity in Chinese hamster ovary cells.
Area of Science:
- Cell biology
- Molecular biology
- Endocrinology
Background:
- GH3 cells naturally produce high levels of endogenous growth hormone and prolactin.
- Understanding promoter activity is crucial for gene expression studies and therapeutic applications.
Purpose of the Study:
- To investigate reporter gene expression from growth hormone and prolactin promoters in engineered GH3 cells.
- To assess the role of the Pit-1 transactivator in enhancing gene expression from these promoters in Chinese hamster ovary (CHO) cells.
Main Methods:
- Engineering GH3 cells with reporter genes under growth hormone and prolactin promoters.
- Measuring reporter protein production.
- Engineering Chinese hamster ovary (CHO) cells to express the Pit-1 transactivator.
- Transfecting reporter genes under the prolactin promoter into Pit-1 expressing CHO cells.
Main Results:
- Engineered GH3 cells exhibited very low reporter protein production from both promoters.
- Pit-1 expression in CHO cells enhanced reporter gene expression from the prolactin promoter.
- Pit-1 expression was insufficient for high-level, stable expression from the growth hormone promoter.
Conclusions:
- Growth hormone and prolactin promoters alone are insufficient for high-level, stable expression, even in permissive cells.
- Pit-1 transactivator alone is insufficient for strong promoter activity from integrated plasmids.
- Cellular context and other factors likely influence the activity of these promoters.