Androgen-receptor-interacting nuclear proteins

Androgen receptor (AR) belongs to the superfamily of nuclear hormone recept ors that employ complex molecular mechanisms to guide the development and p hysiological functions of their target tissues. Our recent work has led to the identification of four novel proteins that recognize AR zinc-finger reg ion (ZFR) both in vivo and in vitro. One is a small nuclear RING-finger pro tein that possesses separate interaction interfaces for AR and for other tr anscription activators such as Spl. The second is a nuclear serine/threonin e protein ki nase (androgen-receptor-interacting nuclear protein kinase; AN PK); however, the receptor itself does not seem to be a substrate for this kinase. The third one is dubbed androgen-receptor-interacting protein 3 (AR IP3) and is a novel member of the PIAS (protein inhibitor of activated STAT ) protein family. The fourth protein, termed ARIP4, is a nuclear ATPase tha t belongs to the SNF2-like family of chromatin remodelling proteins. All fo ur proteins exhibit a punctate nuclear pattern when expressed in cultured c ells. Each protein modulates AR-dependent transactivation in co-transfectio n experiments; their activating functions are not restricted to AR. Current work is aimed at elucidating the biochemical and functional properties of these AR-interacting proteins and at finding the partner proteins that form complexes with them in vivo.