Retinoic acid receptor belongs to a subclass of nuclear receptors that do not form "docking" complexes with hsp90

Dalman, Friedrich C.; Sturzenbecker, Laurie J.; Levin, Arthur A.; Lucas, Debra A.; Perdew, Gary H.; Petkovitch, Martin; Chambon, Pierre; Grippo, Joseph F.; Pratt, William B.

doi:10.1021/bi00236a038

Cited by 91 publications

(46 citation statements)

References 27 publications

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“…Although oncogenic v-Erb A (NR1A1), a derivative of the thyroid hormone receptor, stably interacts with hsp90 in the cytoplasm (29), endogenous type II receptors are not associated with hsp90. For example, neither RXR nor thyroid hormone receptor is associated with hsp90 (30,31). Although PPAR␣ interacts with hsp72 in vitro (21), the association of a hsp90 molecular chaperone with PPAR␣ has not been previously established.…”

Section: Discussionmentioning

confidence: 99%

Evidence That Peroxisome Proliferator-activated Receptor α Is Complexed with the 90-kDa Heat Shock Protein and the Hepatitis Virus B X-associated Protein 2

Sumanasekera

Tien²,

Turpey³

et al. 2003

Journal of Biological Chemistry

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101

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The peroxisome proliferator-activated receptor ␣ (PPAR␣) is a ligand-inducible transcription factor, which belongs to the nuclear receptor superfamily. PPAR␣ mediates the carcinogenic effects of peroxisome proliferators in rodents. In humans, PPAR␣ plays a fundamental role in regulating energy homeostasis via control of lipid metabolism. To study the possible role of chaperone proteins in the regulation of PPAR␣ activity, a monoclonal antibody (mAb) was made against PPAR␣ and designated as 3B6/PPAR. The specificity of mAb 3B6/PPAR in recognizing PPAR␣ was tested in immunoprecipitations using in vitro translated PPAR subtypes. The mAb 3B6/PPAR recognized PPAR␣, failed to bind to PPAR␤ or PPAR␥, and is efficient in both immunoprecipitating and visualizing the receptor on protein blots. The immunoprecipitation of PPAR␣ in mouse liver cytosol using mAb 3B6/PPAR has resulted in the detection of two co-immunoprecipitated proteins, which are heat shock protein 90 (hsp90) and the hepatitis B virus X-associated protein 2 (XAP2). The concomitant depletion of PPAR␣ in hsp90-depleted mouse liver cytosol was also detected. Complex formation between XAP2 and PPAR␣/FLAG was also demonstrated in an in vitro translation binding assay. hsp90 interacts with PPAR␣ in a mammalian two-hybrid assay and binds to the E/F domain. Transient expression of XAP2 co-expressed with PPAR␣ resulted in down-regulation of a peroxisome proliferator response element-driven reporter gene activity. Taken together, these results indicate that PPAR␣ is in a complex with hsp90 and XAP2, and XAP2 appears to function as a repressor. This is the first demonstration that PPAR␣ is stably associated with other proteins in tissue extracts and the first nuclear receptor shown to functionally interact with XAP2.The ability of peroxisome proliferators to activate a receptor in the steroid receptor superfamily was first discovered in 1990, and the cognate protein was designated as PPAR 1 (1). ThePPARs are soluble transcription factors that are activated by a diverse class of lipophilic compounds (2). With the activation of PPAR, a concomitant induction of a number of genes that code for peroxisomal fatty acid metabolizing enzymes was observed in mouse liver. Among these, the peroxisomal enzyme AOx is the most broadly used indicator of peroxisome proliferator action. Transcription of the AOx gene is increased by exposure to the hypolipidemic peroxisome proliferator WY-14,643, and this effect is mediated by a PPRE located 570 base pairs upstream of the transcriptional start site (3). This PPRE contains a direct repeat of the sequence motifs TGACCT and TGTCCT, which is separated by a single nucleotide. A heterodimer of PPAR and RXR binds to PPREs located in upstream regulatory regions of various target genes and the RXR ligand, 9-cis-retinoic acid, increases PPAR/RXR transcriptional activity (4). There are three PPAR subtypes, designated as PPAR␣ (NR1C1), -␤ (NR1C2), and -␥ (NR1C3); and each subtype is capable of binding to DNA after heterodimerizing with RXR (NR2B1) ...

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Section: Discussionmentioning

confidence: 99%

Evidence That Peroxisome Proliferator-activated Receptor α Is Complexed with the 90-kDa Heat Shock Protein and the Hepatitis Virus B X-associated Protein 2

Sumanasekera

Tien²,

Turpey³

et al. 2003

Journal of Biological Chemistry

Self Cite

101

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“…Available crystal structures (18 -25), including that for progesterone receptor, which is most closely related to GR, indicate there is a high degree of overall structural conservation in the LBD of various steroid receptor family members. However, the nuclear receptor group (thyroid hormone receptor and RAR) does not interact with the chaperone proteins (26,27), at least in the "docking" capacity implicated in cytoplasmic retention for the steroid receptors. Furthermore, some of the hydrophobic "contacts" in the steroid binding pocket that are proposed to interact with the LXXLL motif (17) are not conserved between the LBD of GR and some of the nuclear receptors such as RAR.…”

Section: A Real Time Sensing Assay For Nuclear Receptor Ligands 45502mentioning

confidence: 99%

A Glucocorticoid/Retinoic Acid Receptor Chimera That Displays Cytoplasmic/Nuclear Translocation in Response to Retinoic Acid

Mackem¹,

Baumann²,

Hager³

2001

Journal of Biological Chemistry

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Members of the nuclear receptor superfamily play key roles in a host of physiologic and pathologic processes from embryogenesis to cancer. Some members, including the retinoic acid receptor (RAR), are activated by ligand binding but are unaffected in their subcellular distribution, which is predominantly nuclear. In contrast, several members of the steroid receptor family, including the glucocorticoid receptor, are cytoplasmic and only translocate to the nucleus after ligand binding. We have constructed chimeras between RAR and glucocorticoid receptor that selectively respond to RAR agonists but display cytoplasmic localization in the absence of ligand. These chimeric receptors manifest both nuclear translocation and gene activation functions in response to physiological concentrations of RAR ligands. The ability to achieve regulated subcellular trafficking with a heterologous ligand binding domain has implications both for current models of receptor translocation and for structural-functional conservation of ligand binding domains broadly across the receptor superfamily. When coupled to the green fluorescent protein, chimeric receptors offer a powerful new tool to 1) study mechanisms of steroid receptor translocation, 2) detect dynamic and graded distributions of ligands in complex microenvironments such as embryos, and 3) screen for novel ligands of "orphan" receptors in vivo.The glucocorticoid receptor (GR) 1 is a member of the translocating class of steroid receptors. Unliganded GR is found in the cytoplasm and moves rapidly into the nucleus in response to hormone stimulation. Other members of the nuclear receptor superfamily are either complex in their intracellular distributions (e.g. mineralocorticoid receptor (1), progesterone receptor (2, 3), androgen receptor (4), and dioxin receptor (5)) or are found primarily in the nucleus (e.g. estrogen receptor (6), thyroid hormone receptor (see Refs. 7 and 8), and retinoic acid receptor (RAR; see Refs. 7 and 8)). The recent characterization of functional GFP fusions with the steroid/nuclear receptors allows study of real time movement for these molecules within living cells (9). The unliganded GFP-GR is found completely in the cytoplasm, whereas the hormone-activated receptor is located almost exclusively in the nucleus shortly after hormone activation (9 -11). Because nuclear translocation by this intrinsically fluorescent receptor is quite dramatic and easily monitored in real time in vivo, it can provide a straightforward methodology to detect physiological concentrations of receptor ligand in the cellular environment.The availability of chimeric proteins with the nuclear/cytoplasmic translocation properties of GR, and the ligand responsiveness of the nuclear receptors, would provide a powerful translocation assay for nuclear receptor ligands and potentially for novel analogues, as well. Many chimeric receptors have been described (e.g. see Ref. 12), but these fusions have been characterized exclusively in terms of their gene activation potential. We describ...

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“…The ER/RAR␣/ER construct had the C region of RAR␣ (cDNA for amino acids 88 to 153) replacing the C region of ER (cDNA for amino acids 185 to 250). 30 The plasmid, pSV2-neo, has been described previously. 31 Cell culture and generation of stable transfectants CV-1, COS-1, and F9 cells were maintained as described.…”

Section: Plasmid Constructionmentioning

confidence: 99%

Characterization of the chimeric retinoic acid receptor RARα/VDR

et al. 1998

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Retinoic acid receptor belongs to a subclass of nuclear receptors that do not form "docking" complexes with hsp90

Cited by 91 publications

References 27 publications

Evidence That Peroxisome Proliferator-activated Receptor α Is Complexed with the 90-kDa Heat Shock Protein and the Hepatitis Virus B X-associated Protein 2

Evidence That Peroxisome Proliferator-activated Receptor α Is Complexed with the 90-kDa Heat Shock Protein and the Hepatitis Virus B X-associated Protein 2

A Glucocorticoid/Retinoic Acid Receptor Chimera That Displays Cytoplasmic/Nuclear Translocation in Response to Retinoic Acid

Characterization of the chimeric retinoic acid receptor RARα/VDR

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