title: Ligand-independent orphan receptor TR2 activation by phosphorylation at the DNA-binding domain.
abstract: In a previous report we demonstrated protein kinase C (PKC)-mediated phosphorylation of the ligand-binding domain (LBD) of orphan nuclear receptor TR2. In this report, we provide the evidence of PKC-mediated phosphorylation of the DNA-binding domain (DBD) of TR2. Two PKC target sites were predicted within the DBD, at Ser-170 and Ser-185, but only Ser-185 was confirmed by MS. Phosphorylation of DBD facilitated DNA binding of the TR2 receptor and its recruiting of coactivator p300/CBP-associated factor (P/CAF). Ser-185 was required for DNA binding, whereas both Ser-170 and Ser-185 were necessary for receptor interaction with P/CAF. The P/CAF-interacting domain of TR2 was located in its DBD. A double mutant (Ser-170 and Ser-185) of TR2 significantly lowered the activation of its target gene RARbeta2. This study provides the first evidence for ligand-independent activation of TR2 orphan receptor through PTM at the DBD, which enhanced its DNA-binding ability and interaction with coactivator P/CAF.
authors.affiliation: Department of Pharmacology, University of Minnesota Medical School, 321 Church Street SE, Minneapolis, MN 55455, USA.
authors.forename: Shaukat Ali
authors.initials: SA
authors.lastname: Khan
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Park
authors.forename: M D Mostaqul
authors.initials: MD
authors.lastname: Huq
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Wei
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002853:Chromatography, Liquid; D004247:DNA / Q000378:metabolism*; D017931:DNA Primers; D024202:Electrophoretic Mobility Shift Assay; D047468:Immunoprecipitation; D008024:Ligands; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D018124:Receptors, Tumor Necrosis Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053240:Receptors, Tumor Necrosis Factor, Member 14; D011991:Receptors, Virus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012694:Serine / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D008024:Ligands; D018124:Receptors, Tumor Necrosis Factor; D053240:Receptors, Tumor Necrosis Factor, Member 14; D011991:Receptors, Virus; D012694:Serine; D004247:DNA