Endocrine Abstracts

The Androgen Receptor (AR) is a ligand dependent transcription factor that regulates the development and maintenance of the male reproductive system. Previous studies in AIS have demonstrated ligand binding domain mutations resulting in decreased trans-activation activity through reduced N-terminal/C-terminal interaction of the AR, despite unaltered ligand binding ability.
We have introduced mutations in the hinge region of the Androgen Receptor (AR) and assessed the effect on interactions between the N-terminus and C-terminus of the protein.
Six single base substitution mutations (G627V, R629W, L637R, A645D, P651R, I664N) were created in the hinge region of the AR by site-directed mutagenesis. The functional consequences of these mutations were assessed in vitro using a luciferase-based trans-activation assay and a mammalian two-hybrid assay. In the majority, hinge mutations did not affect either trans-activation ability or the N/C interaction potential. One mutation located in the early hinge region, R629W, was shown to influence N-terminal/C-terminal interaction. Controversially, this did not affect trans-activation activity, which was comparable to that of wild-type AR.
These data suggest that trans-activation ability and N/C interaction can function independently in the AR, and that the hinge region may have a regulatory role.