title: PO(2)-dependent differential regulation of multidrug resistance 1 gene expression by the c-Jun NH2-terminal kinase pathway.
abstract: Hypoxia-induced multidrug resistance 1 (MDR1) gene expression is known to be mediated by c-Jun NH(2)-terminal kinase (JNK) activation. However, the molecular mechanisms underlying this action of JNK remain elusive. On the contrary, there has been increasing evidence for a negative correlation of JNK activity with MDR1 expression under normoxic conditions. Here, we present evidence that the JNK pathway represses MDR1 expression in normoxia and activates MDR1 expression in hypoxia. Our data show that JNK pathway-induced MDR1 repression in normoxia is mediated by increased c-Jun binding to activator protein 1 site, located in the MDR1 promoter, and requires the activity of histone deacetylase 5. In contrast, JNK pathway-induced MDR1 activation in hypoxia is independent of the activator protein 1 site. Rather, this action is dependent on increased hypoxia-inducible factor 1 (HIF1) binding to the hypoxia response element in the MDR1 promoter, which is promoted by the interaction of HIF1alpha with c-Jun in the nucleus and requires the activity of the p300/CBP (CREB-binding protein) coactivator.
authors: Department of Genetics and Cell Biology, Key Laboratory of Bioactive Materials (Ministry of Education), College of Life Sciences, Nankai University, Tianjin 300071, China.
authors: Min
authors: M
authors: Liu
authors: Dengwen
authors: D
authors: Li
authors: Ritu
authors: R
authors: Aneja
authors: Harish C
authors: HC
authors: Joshi
authors: Songbo
authors: S
authors: Xie
authors: Chao
authors: C
authors: Zhang
authors: Jun
authors: J
authors: Zhou
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006655:Histone Deacetylases / Q000378:metabolism; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000502:physiology*; D011401:Promoter Regions, Genetic; D020218:Response Elements; D050880:p300-CBP Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007527:Isoenzymes; D050880:p300-CBP Transcription Factors; D048031:JNK Mitogen-Activated Protein Kinases; D006655:Histone Deacetylases