The human TR2 orphan receptor (TR2), initially isolated from testis and prostate cDNA libraries, is a member of the steroid receptor superfamily. TR2 can regulate several target genes via binding to a consensus response element (AGGTCA) in direct repeat orientation (AGGTCAX (n) AGGTCA, n ؍ 0 -6). Here we show that TR2 is able to induce the expression of human papilloma virus type 16 (HPV-16) genes via binding to a DR4 response element in the long control region of HPV-16. Additionally, one of the HPV-16 gene products, the E6 oncogene, regulates TR2 gene expression. A likely mechanism for this regulation involves E6-mediated degradation of the tumor suppressor p53, a protein known to suppress TR2 expression. Together our data provide evidence for feedback regulation between TR2 and HPV-16, which represents a novel regulatory pathway involving a member of the steroid receptor superfamily and the HPV-16 DNA tumor virus.Orphan receptors, or receptors without known ligands, make up the vast majority of members of the steroid receptor superfamily (1-3). Members of this family are characterized by a highly conserved DNA-binding domain (DBD) 1 and a carboxylterminal ligand-binding domain. The conserved amino acid sequence within the DBDs of these receptors is predicted to form two zinc finger motifs (1). Additionally, steroid receptors bind to specific DNA sequences known as hormone response elements (HREs) through which regulation of target gene expression may occur (1). The cDNA of the human TR2 orphan receptor (TR2) was isolated from the screening of human testis and prostate cDNA libraries for the androgen receptor. In the screening, an oligonucleotide probe homologous to the highly conserved DBD of the glucocorticoid receptor was used (2). Four TR2 cDNA clones (TR2-5, -7, -9, and -11) were isolated and found to share identical sequences in the N-terminal and DBD regions yet were found to differ in the length of the C-terminal putative ligand-binding domain (3).Through further study of TR2, it was found that this orphan receptor binds to a consensus HRE composed of a direct repeat (DR) with variable spacing (AGGTCAX (n) AGGTCA, n ϭ 0 -6) (4). Using the known TR2 HRE sequence as a guide, it was determined that TR2 has modulatory effects on several signaling pathways such as those involving retinoic acid (4), thyroid hormone (5), and ciliary neurotrophic factor (6). Moreover, expression of the erythropoietin gene (7), aldolase gene (8), histamine H1 receptor (9), and simian virus 40 (SV40) (10) is also regulated by TR2. To add to the list of TR2-responsive genes, we have found a TR2 DR4 consensus site within the long control region (LCR) of the human papilloma virus type 16 (HPV-16). In this report, we show that TR2 is able to bind the consensus response element (DR4RE) within the HPV-16 gene and modulate HPV-16 expression. The human papilloma virus is a common sexually transmitted pathogen that is linked to increased risk for the development of cervical neoplasia, one of the most common cancers in women throughou...