Atomic structure of mutant PPARγ LBD complexed with 15d‐PGJ<sub>2</sub>: Novel modulation mechanism of PPARγ/RXRα function by covalently bound ligands

Waku, Tsuyoshi; Shiraki, Takuma; Oyama, Takuji; Morikawa, Kosuke

doi:10.1016/j.febslet.2008.12.017

Cited by 47 publications

(39 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Subsequent studies using crystallography 28 or competitive ligand-binding assays revealed that these synthetic ligands and others bind to the canonical LBP of PPARγ; a variable-sized pocket within the interior of LBD conserved across the NR superfamily. Around the same time, the first identification of endogenous PPARγ ligands were made 29,30 , and more recent studies have revealed that endogenous ligands and synthetic ligands have overlapping binding sites in the PPARγ canonical LBP 24,26,31-33 . Thus, synthetic ligands are presumed to bind to PPARγ by competing with endogenous ligands for the same binding site.…”

Section: Discussionmentioning

confidence: 99%

An alternate binding site for PPARγ ligands

et al. 2014

View full text Add to dashboard Cite

PPARγ is a target for insulin sensitizing drugs such as glitazones, which improve plasma glucose maintenance in patients with diabetes. Synthetic ligands have been designed to mimic endogenous ligand binding to a canonical ligand-binding pocket to hyperactivate PPARγ. Here we reveal that synthetic PPARγ ligands also bind to an alternate site, leading to unique receptor conformational changes that impact coregulator binding, transactivation and target gene expression. Using structure-function studies we show that alternate site binding occurs at pharmacologically relevant ligand concentrations, and is neither blocked by covalently bound synthetic antagonists nor by endogenous ligands indicating non-overlapping binding with the canonical pocket. Alternate site binding likely contributes to PPARγ hyperactivation in vivo, perhaps explaining why PPARγ full and partial or weak agonists display similar adverse effects. These findings expand our understanding of PPARγ activation by ligands and suggest that allosteric modulators could be designed to fine tune PPARγ activity without competing with endogenous ligands.

show abstract

Section: Discussionmentioning

confidence: 99%

An alternate binding site for PPARγ ligands

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In the molecular docking experiment, MH was predicted to bind at the identical ligand binding site as other PPARg agonists, such as 15-deoxy-PGJ2 (Waku et al, 2009) and the fatty acid ligand LNO2 (Cheng et al, 2009 Figure 1D). One hydrogen bond was observed between the hydroxyl group of the MH and the hydroxyl side chain of Ser 289 in PPARg ( Figure 1E).…”

Section: Mh Increased the Expression Transcription And Dna Binding Amentioning

confidence: 99%

4‐O‐methylhonokiol, a PPARγ agonist, inhibits prostate tumour growth: p21‐mediated suppression of NF‐κB activity

Lee

Ban

et al. 2013

British J Pharmacology

View full text Add to dashboard Cite

BACKGROUND AND PURPOSEThe effects of 4-O-methylhonokiol (MH), a constituent of Magnolia officinalis, were investigated on human prostate cancer cells and its mechanism of action elucidated. EXPERIMENTAL APPROACHThe anti-cancer effects of MH were examined in prostate cancer and normal cells. The effects were validated in vivo using a mouse xenograft model. KEY RESULTSMH increased the expression of PPARg in prostate PC-3 and LNCap cells. The pull-down assay and molecular docking study indicated that MH directly binds to PPARg. MH also increased transcriptional activity of PPARg but decreased NF-kB activity. MH inhibited the growth of human prostate cancer cells, an effect attenuated by the PPARg antagonist GW9662. MH induced apoptotic cell death and this was related to G0-G1 phase cell cycle arrest. MH increased the expression of the cell cycle regulator p21, and apoptotic proteins, whereas it decreased phosphorylation of Rb and anti-apoptotic proteins. Transfection of PC3 cells with p21 siRNA or a p21 mutant plasmid on the cyclin D1/ cycline-dependent kinase 4 binding site abolished the effects of MH on cell growth, cell viability and related protein expression. In the animal studies, MH inhibited tumour growth, NF-kB activity and expression of anti-apoptotic proteins, whereas it increased the transcriptional activity and expression of PPARg, and the expression of apoptotic proteins and p21 in tumour tissues. CONCLUSIONS AND IMPLICATIONMH inhibits growth of human prostate cancer cells through activation of PPARg, suppression of NF-kB and arrest of the cell cycle. Thus, MH might be a useful tool for treatment of prostate cancer. AbbreviationCDK, cycline-dependent kinase; CNBr, cyanogen bromide; DAPI, 4',6-diamidino-2-phenylindole; GSK-3 b, glycogen synthase kinase 3 b; IAP1, inhibitor of apoptosis 1; iNOS, inducible NOS; MH, 4-O-methylhonokiol

show abstract

“…Oxidized unsaturated fatty acids effectively stabilize the Ω-loop region through formation of a covalent bond with Cys285 (16). Morikawa and colleagues proposed a model involving conformational changes of the PPARγ LBD during activation by 15-deoxy-∆ 12,14 -prostaglandin J 2 (15d-PGJ 2 ), where covalent modification of Cys285 may act as a "switch" for activation.The non-covalently bound, inactive intermediate complex is designated as the "docked state" and the covalently bound, active complex as the "locked state"(32). The transcriptional activity of endogenous unsaturated fatty acids is specific for ligand type.For example, 15-oxo-eicosatetraenoic acid (15-oxo-ETE) and 15d-PGJ 2 activate PPARγ transcription while 8-oxo-ETE does not, though all three can form a covalent linkage with Cys285 through an α,β-unsaturated ketone(33).…”

mentioning

confidence: 99%

Identification of a New Type of Covalent PPARγ Agonist using a Ligand-Linking Strategy

Ohtera¹,

Miyamae²,

Yoshida³

et al. 2015

ACS Chem. Biol.

View full text Add to dashboard Cite

Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor that plays an important role in adipogenesis and glucose metabolism. The ligand-binding pocket (LBP) of PPARγ has a large Y-shaped cavity with multiple subpockets where multiple ligands can simultaneously bind and cooperatively activate PPARγ. Focusing on this unique property of the PPARγ LBP, we describe a novel two-step cell-based strategy to develop PPARγ ligands. First, a combination of ligands that cooperatively activates PPARγ was identified using a luciferase reporter assay. Second, hybrid ligands were designed and synthesized. For proof of concept, we focused on covalent agonists, which activate PPARγ through a unique activation mechanism regulated by a covalent linkage with the Cys285 residue in the PPARγ LBP. Despite their biological significance and pharmacological potential, few covalent PPARγ agonists are known except for endogenous fatty acid metabolites. With our strategy, we determined that plant-derived cinnamic acid derivatives cooperatively activated PPARγ by combining with GW9662, an irreversible antagonist. GW9662 covalently reacts with the Cys285 residue. A docking study predicted that a cinnamic acid derivative can bind to the open cavity in GW9662-bound PPARγ LBP. On the basis of the putative binding mode, structures of both ligands were linked successfully to create a potent PPARγ agonist, which enhanced the transactivation potential of PPARγ at submicromolar levels through covalent modification of Cys285. Our approach could lead to the discovery of novel high-potency PPARγ agonists.

show abstract

Atomic structure of mutant PPARγ LBD complexed with 15d‐PGJ₂: Novel modulation mechanism of PPARγ/RXRα function by covalently bound ligands

Cited by 47 publications

References 26 publications

An alternate binding site for PPARγ ligands

An alternate binding site for PPARγ ligands

4‐O‐methylhonokiol, a PPARγ agonist, inhibits prostate tumour growth: p21‐mediated suppression of NF‐κB activity

Identification of a New Type of Covalent PPARγ Agonist using a Ligand-Linking Strategy

Contact Info

Product

Resources

About

Atomic structure of mutant PPARγ LBD complexed with 15d‐PGJ2: Novel modulation mechanism of PPARγ/RXRα function by covalently bound ligands

Cited by 47 publications

References 26 publications

An alternate binding site for PPARγ ligands

An alternate binding site for PPARγ ligands

4‐O‐methylhonokiol, a PPARγ agonist, inhibits prostate tumour growth: p21‐mediated suppression of NF‐κB activity

Identification of a New Type of Covalent PPARγ Agonist using a Ligand-Linking Strategy

Contact Info

Product

Resources

About

Atomic structure of mutant PPARγ LBD complexed with 15d‐PGJ₂: Novel modulation mechanism of PPARγ/RXRα function by covalently bound ligands