Abstract: This invention relates to a novel nuclear protein which interacts with the androgen receptor in vivo and in vitro, and which also possesses ATPase activity. The invention concerns also mRNA and DNA sequences encoding said protein.

Abstract: The present invention is directed to methods for determining the androgenic or anti-androgenic activity of a sample and to a cell useful in these methods. To determine androgenic activity, the sample is contacted and incubated with a cell comprising i) a luciferase reporter plasmid, ii) a fusion protein comprising a ligand-binding domain of the androgen receptor and a Gal4 DNA-binding domain, said fusion protein being able to bind to binding sites in said luciferase reporter plasmid, iii) a fusion protein comprising an N-terminal region of the androgen receptor and a transcriptional activation domain, and iv) an androgen receptor-interacting protein 3. The cell is then lysed and the luciferase activity of the lysate is measured. The measured luciferase activity is compared to that obtained by repeating the above method except that a control is added instead of the sample, to give the relative luciferase activity of the sample.