We have isolated a human testis complementary DNA clone on the basis of homology to the DNA binding domain of steroid receptors. Expression of this complementary DNA, which we call TR2, produces a 52 kd DNA binding protein that does not bind significantly to any known steroids. Northern blot analysis has shown that TR2 mRNA is about 2.5 kilobases (kb) and is relatively abundant in androgen-sensitive organs, such as ventral prostate and seminal vesicle. Dot blot hybridization indicates that TR2 mRNA levels increased after castration of rats, and this increase is reversed by 5 alpha-dihydrotestosterone injection. This evidence suggests that TR2 mRNA levels are negatively controlled by androgen in the rat ventral prostate.