The GAL4-UAS system is a powerful technique for studying of gene expression in some model organisms such as Drosophila. It can also be adapted to study receptor ligand-binding functions in vitro in cell culture. The system is based on the properties of the yeast GAL4 transcription factor and has two main independent parts:
Part-I; The GAL4 gene or regulatory elements, encoding the yeast transcription activator protein GAL4
Part-II; The UAS (Upstream Activation Sequence), an enhancer to which GAL4 specifically binds to activate gene transcription.
 
Expression of GAL4 can be controlled with defined promoter and targeted gene of interest can be located at downstream of GAL4. On the other hands Part-II can be modified by adding a reporter gene like luciferase at downstream of UAS. By activation of part-I and at the presence of part-II, GAL4 can bind to UAS and express luciferase (see below diagram). The GAL4-UAS system has many applications and can be used for cell or tissue-specific genetic mutant rescue, gene overexpression, RNA interference screens. Generating a robust Part-I or Part-II can be difficult and time consuming. To facilitate this process here we offer a CHO stable cell line that express part-II of GAL4-UAS system and is ready for transfection of Part-I. By designing your own Part-I you will be able to monitor expression of your gene of interest.