TY - JOUR
T1 - Human papilloma virus 16 E6 oncoprotein inhibits retinoic X receptor-mediated transactivation by targeting human ADA3 coactivator
AU - Zeng, Musheng
AU - Kumar, Ajay
AU - Meng, Gaoyuan
AU - Gao, Qingshen
AU - Dimri, Goberdhan
AU - Wazer, David
AU - Band, Hamid
AU - Band, Vimla
PY - 2002/11/22
Y1 - 2002/11/22
N2 - The expression of human papillomavirus (HPV) E6 oncoprotein is causally linked to high-risk HPV-associated human cancers. We have recently isolated hADA3, the human homologue of yeast transcriptional co-activator yADA3, as a novel E6 target. Human ADA3 binds to the high-risk (cancer-associated) but not the low-risk HPV E6 proteins and to immortalization-competent but not to immortalization-defective HPV16 E6 mutants, suggesting a role for the perturbation of hADA3 function in E6-mediated oncogenesis. We demonstrate here that hADA3 directly binds to the retinoic X receptor (RXR)α in vitro and in vivo. Using chromatin immunoprecipitation, we show that hADA3 is part of activator complexes bound to the native RXR response elements within the promoter of the cyclin-dependent kinase inhibitor gene p21. We show that hADA3 enhances the RXRα-mediated sequence-specific transactivation of retinoid target genes, cellular retinoic acid-binding protein II and p21. Significantly, we demonstrate that E6 inhibits the RXRα-mediated transactivation of target genes, implying that perturbation of RXR-mediated transactivation by E6 could contribute to HPV oncogenesis.
AB - The expression of human papillomavirus (HPV) E6 oncoprotein is causally linked to high-risk HPV-associated human cancers. We have recently isolated hADA3, the human homologue of yeast transcriptional co-activator yADA3, as a novel E6 target. Human ADA3 binds to the high-risk (cancer-associated) but not the low-risk HPV E6 proteins and to immortalization-competent but not to immortalization-defective HPV16 E6 mutants, suggesting a role for the perturbation of hADA3 function in E6-mediated oncogenesis. We demonstrate here that hADA3 directly binds to the retinoic X receptor (RXR)α in vitro and in vivo. Using chromatin immunoprecipitation, we show that hADA3 is part of activator complexes bound to the native RXR response elements within the promoter of the cyclin-dependent kinase inhibitor gene p21. We show that hADA3 enhances the RXRα-mediated sequence-specific transactivation of retinoid target genes, cellular retinoic acid-binding protein II and p21. Significantly, we demonstrate that E6 inhibits the RXRα-mediated transactivation of target genes, implying that perturbation of RXR-mediated transactivation by E6 could contribute to HPV oncogenesis.
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U2 - 10.1074/jbc.M208447200
DO - 10.1074/jbc.M208447200
M3 - Article
C2 - 12235159
AN - SCOPUS:0037160037
VL - 277
SP - 45611
EP - 45618
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 47
ER -