title: T0070907, a selective ligand for peroxisome proliferator-activated receptor gamma, functions as an antagonist of biochemical and cellular activities.
abstract: The nuclear hormone receptor peroxisome proliferator-activated receptor gamma (PPARgamma (NR1C3)) plays a central role in adipogenesis and is the molecular target for the thiazolidinedione (TZD) class of antidiabetic drugs. In a search for novel non-TZD ligands for PPARgamma, T0070907 was identified as a potent and selective PPARgamma antagonist. With an apparent binding affinity (concentration at 50% inhibition of [(3)H]rosiglitazone binding or IC(50)) of 1 nm, T0070907 covalently modifies PPARgamma on cysteine 313 in helix 3 of human PPARgamma2. T0070907 blocked PPARgamma function in both cell-based reporter gene and adipocyte differentiation assays. Consistent with its role as an antagonist of PPARgamma, T0070907 blocked agonist-induced recruitment of coactivator-derived peptides to PPARgamma in a homogeneous time-resolved fluorescence-based assay and promoted recruitment of the transcriptional corepressor NCoR to PPARgamma in both glutathione S-transferase pull-down assays and a PPARgamma/retinoid X receptor (RXR) alpha-dependent gel shift assay. Studies with mutant receptors suggest that T0070907 modulates the interaction of PPARgamma with these cofactor proteins by affecting the conformation of helix 12 of the PPARgamma ligand-binding domain. Interestingly, whereas the T0070907-induced NCoR recruitment to PPARgamma/RXRalpha heterodimer can be almost completely reversed by the simultaneous treatment with RXRalpha agonist LGD1069, T0070907 treatment has only modest effects on LGD1069-induced coactivator recruitment to the PPARgamma/RXRalpha heterodimer. These results suggest that the activity of PPARgamma antagonists can be modulated by the availability and concentration of RXR agonists. T0070907 is a novel tool for the study of PPARgamma/RXRalpha heterodimer function.
authors.affiliation: Tularik Inc., South San Francisco, California 94080, USA.
authors.forename: Gary
authors.initials: G
authors.lastname: Lee
authors.forename: Fabienne
authors.initials: F
authors.lastname: Elwood
authors.forename: John
authors.initials: J
authors.lastname: McNally
authors.forename: Jennifer
authors.initials: J
authors.lastname: Weiszmann
authors.forename: Michelle
authors.initials: M
authors.lastname: Lindstrom
authors.forename: Kate
authors.initials: K
authors.lastname: Amaral
authors.forename: Motonao
authors.initials: M
authors.lastname: Nakamura
authors.forename: Shichang
authors.initials: S
authors.lastname: Miao
authors.forename: Ping
authors.initials: P
authors.lastname: Cao
authors.forename: R Marc
authors.initials: RM
authors.lastname: Learned
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism; D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D001549:Benzamides / Q000737:chemistry / Q000494:pharmacology*; D000077610:Bexarotene; D002454:Cell Differentiation; D002460:Cell Line; D003545:Cysteine / Q000737:chemistry; D019281:Dimerization; D004305:Dose-Response Relationship, Drug; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008024:Ligands; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D047488:Retinoid X Receptors; D013050:Spectrometry, Fluorescence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D013997:Time Factors; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D016588:Anticarcinogenic Agents; D001549:Benzamides; D008024:Ligands; D010455:Peptides; D011725:Pyridines; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins; D047488:Retinoid X Receptors; C458508:T 0070907; D013764:Tetrahydronaphthalenes; D014157:Transcription Factors; D000077610:Bexarotene; D005982:Glutathione Transferase; D003545:Cysteine