In particular, transfected adipocytes comprising Ob gene promoters operably linked to a reporter are used in high-throughput pharmaceutical screens.

The collision construct is used to screen inhibitors of the second regulatory sequence and the second promoter whereby a functional inhibitor causes an enhanced signal of the reporter gene.

A specific interaction between two partners may be visualized through dimerization of the Irelp moiety which, either. directly or indirectly, results in a detection means, for example, the expression of a selectable reporter gene.

Accordingly, a cell in which IRES-mdiated translation of the counter-selectable reporter gene is selected, thereby identifying a compound that inhibits IRES-mediated translation.

Depending on the type of reporter gene used, its expression can positively or negatively influence cell growth, thus allowing selection of both stimulation and inhibition of protein-protein interactions.

Polypeptides having binding activity are identified by their capacity to activate transcription of a reporter gene via binding of the polypeptide being screened to the selected RNA recognition sequence.

CAT assay (French : CAT, essai) Reporter gene assay used to measure activity of a promoter under different conditions, such as to define elements of a promoter or to study signals that activates an intact promoter.

Another aspect of the invention is a mutated constitutively active GPR88, i.e., having increased basal activity relative to a wild-type GPR88 polypeptide, and a modified reporter gene which provides for a faster assay readout.