title: SDS3 interacts with ARNT in an AhR ligand-specific manner regulating expression of cKrox and S100A4 in CD4+CD8+ DPK thymocytes differentiation.
abstract: To study mechanisms underlying differential effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and benzo(a)pyrene (B(a)P) on thymocyte differentiation, we examined effects of AhR ligands on the differentiation of DPK cells, a CD4(+)CD8(+) thymic lymphoma cell line which can differentiate into CD4(+)CD8(-) thymocytes. In contrast to TCDD, which inhibited the differentiation, B(a)P showed little effect. Antigen-mediated up-regulation of S100A4, S100A6, galectin-1, and TRAF5-like protein was remarkably suppressed by TCDD, but slightly by B(a)P. Immunoprecipitation using anti-ARNT Ab revealed that SDS3, a component of the Sin3/HDAC repressor complex, was associated with ARNT only when DPK cells were incubated with TCDD. Expression of cKrox S100A4 was derepressed when SDS3 protein was reduced. These results indicate that although it is generally known that many AhR ligands such as TCDD and B(a)P function mainly by the AhR/ARNT complex, ligand-specific interaction between SDS3 and ARNT exerts differential effects on the expression of genes associated with thymocyte differentiation.
authors.affiliation: Department of Biology, Changwon National University, Changwon, Kyungnam 641-773, South Korea.
authors.forename: Dong-Min
authors.initials: DM
authors.lastname: Lee
authors.forename: Seung-Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Jeong
authors.forename: Sung-Jun
authors.initials: SJ
authors.lastname: Hwang
authors.forename: Joo-Hung
authors.initials: JH
authors.lastname: Park
mesh_terms: D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000378:metabolism*; D015704:CD4 Antigens / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins; D037483:Galectin 1 / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D008024:Ligands; D008213:Lymphocyte Activation / Q000187:drug effects; D000072317:Polychlorinated Dibenzodioxins / Q000633:toxicity; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; D060168:Thymocytes / Q000502:physiology*; D015854:Up-Regulation
chemical_list: D015704:CD4 Antigens; D016827:CD8 Antigens; D004268:DNA-Binding Proteins; D037483:Galectin 1; D008024:Ligands; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D012097:Repressor Proteins; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C576731:SUDS3 protein, human; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; C077591:S100A4 protein, human