Farnesoid X receptor

Farnesoid X receptor

Nuclear receptor subfamily 1, group H, member 4
PDB rendering based on 1osh.
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols  ; BAR; FXR; HRR-1; HRR1; RIP14
External IDs IUPHAR: ChEMBL: GeneCards:
RNA expression pattern
Species Human Mouse
RefSeq (mRNA)
RefSeq (protein)
Location (UCSC)
PubMed search

The bile acid receptor (BAR), also known as farnesoid X receptor (FXR) or NR1H4 (nuclear receptor subfamily 1, group H, member 4) is a nuclear receptor that is encoded by the NR1H4 gene in humans.[1][2]


  • Function 1
  • Interactions 2
  • Ligands 3
  • References 4
  • Further reading 5
  • External links 6


FXR is expressed at high levels in the liver and intestine. Chenodeoxycholic acid and other bile acids are natural ligands for FXR. Similar to other nuclear receptors, when activated, FXR translocates to the cell nucleus, forms a dimer (in this case a heterodimer with RXR) and binds to hormone response elements on DNA, which up- or down-regulates the expression of certain genes.[2]

One of the primary functions of FXR activation is the suppression of cholesterol 7 alpha-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis from cholesterol. FXR does not directly bind to the CYP7A1 promoter. Rather, FXR induces expression of small heterodimer partner (SHP), which then functions to inhibit transcription of the CYP7A1 gene. In this way a negative feedback pathway is established in which synthesis of bile acids is inhibited when cellular levels are already high. FXR has also been found to be important in regulation of hepatic triglyceride levels.[3] Studies have also shown the FXR to regulate the expression and activity of epithelial transport proteins involved in fluid homestasis in the intestine, such as the cystic fibrosis conductance transmembrane regulator (CFTR)[4]


Farnesoid X receptor has been shown to interact with:


A number of ligands for FXR are known, of both natural and synthetic origin.[7][8][9]



  1. ^ "Entrez Gene: NR1H4 nuclear receptor subfamily 1, group H, member 4". 
  2. ^ a b Forman BM, Goode E, Chen J, Oro AE, Bradley DJ, Perlmann T, Noonan DJ, Burka LT, McMorris T, Lamph WW, Evans RM, Weinberger C (Jun 1995). "Identification of a nuclear receptor that is activated by farnesol metabolites". Cell 81 (5): 687–93.  
  3. ^ Jiao Y, Lu Y, Li XY (Jan 2015). "Farnesoid X receptor: a master regulator of hepatic triglyceride and glucose homeostasis". Acta Pharmacologica Sinica 36 (1): 44–50.  
  4. ^ Mroz MS, Keating N, Ward JB, Sarker R, Amu S, Aviello G, Donowitz M, Fallon PG, Keely SJ (May 2014). "Farnesoid X receptor agonists attenuate colonic epithelial secretory function and prevent experimental diarrhoea in vivo". Gut 63 (5): 808–17.  
  5. ^ Zhang Y, Castellani LW, Sinal CJ, Gonzalez FJ, Edwards PA (Jan 2004). "Peroxisome proliferator-activated receptor-gamma coactivator 1alpha (PGC-1alpha) regulates triglyceride metabolism by activation of the nuclear receptor FXR". Genes & Development 18 (2): 157–69.  
  6. ^ Seol W, Choi HS, Moore DD (Jan 1995). "Isolation of proteins that interact specifically with the retinoid X receptor: two novel orphan receptors". Molecular Endocrinology 9 (1): 72–85.  
  7. ^ Fiorucci S, Zampella A, Distrutti E (2012). "Development of FXR, PXR and CAR agonists and antagonists for treatment of liver disorders". Current Topics in Medicinal Chemistry 12 (6): 605–24.  
  8. ^ Fiorucci S, Mencarelli A, Distrutti E, Zampella A (May 2012). "Farnesoid X receptor: from medicinal chemistry to clinical applications". Future Medicinal Chemistry 4 (7): 877–91.  
  9. ^ Vaz B, de Lera ÁR (Nov 2012). "Advances in drug design with RXR modulators". Expert Opinion on Drug Discovery 7 (11): 1003–16.  
  10. ^ Ricketts ML, Boekschoten MV, Kreeft AJ, Hooiveld GJ, Moen CJ, Müller M, Frants RR, Kasanmoentalib S, Post SM, Princen HM, Porter JG, Katan MB, Hofker MH, Moore DD (Jul 2007). "The cholesterol-raising factor from coffee beans, cafestol, as an agonist ligand for the farnesoid and pregnane X receptors". Molecular Endocrinology 21 (7): 1603–16.  

Further reading

  • Kalaany NY, Mangelsdorf DJ (2006). "LXRS and FXR: the yin and yang of cholesterol and fat metabolism". Annual Review of Physiology 68: 159–91.  
  • Kuipers F, Stroeve JH, Caron S, Staels B (Jun 2007). "Bile acids, farnesoid X receptor, atherosclerosis and metabolic control". Current Opinion in Lipidology 18 (3): 289–97.  
  • Seol W, Choi HS, Moore DD (Jan 1995). "Isolation of proteins that interact specifically with the retinoid X receptor: two novel orphan receptors". Molecular Endocrinology 9 (1): 72–85.  
  • Zavacki AM, Lehmann JM, Seol W, Willson TM, Kliewer SA, Moore DD (Jul 1997). "Activation of the orphan receptor RIP14 by retinoids". Proceedings of the National Academy of Sciences of the United States of America 94 (15): 7909–14.  
  • Makishima M, Okamoto AY, Repa JJ, Tu H, Learned RM, Luk A, Hull MV, Lustig KD, Mangelsdorf DJ, Shan B (May 1999). "Identification of a nuclear receptor for bile acids". Science 284 (5418): 1362–5.  
  • Parks DJ, Blanchard SG, Bledsoe RK, Chandra G, Consler TG, Kliewer SA, Stimmel JB, Willson TM, Zavacki AM, Moore DD, Lehmann JM (May 1999). "Bile acids: natural ligands for an orphan nuclear receptor". Science 284 (5418): 1365–8.  
  • Bramlett KS, Yao S, Burris TP (Dec 2000). "Correlation of farnesoid X receptor coactivator recruitment and cholesterol 7alpha-hydroxylase gene repression by bile acids". Molecular Genetics and Metabolism 71 (4): 609–15.  
  • Stegh AH, Barnhart BC, Volkland J, Algeciras-Schimnich A, Ke N, Reed JC, Peter ME (Feb 2002). "Inactivation of caspase-8 on mitochondria of Bcl-xL-expressing MCF7-Fas cells: role for the bifunctional apoptosis regulator protein". The Journal of Biological Chemistry 277 (6): 4351–60.  
  • Cui J, Heard TS, Yu J, Lo JL, Huang L, Li Y, Schaeffer JM, Wright SD (Jul 2002). "The amino acid residues asparagine 354 and isoleucine 372 of human farnesoid X receptor confer the receptor with high sensitivity to chenodeoxycholate". The Journal of Biological Chemistry 277 (29): 25963–9.  
  • Huber RM, Murphy K, Miao B, Link JR, Cunningham MR, Rupar MJ, Gunyuzlu PL, Haws TF, Kassam A, Powell F, Hollis GF, Young PR, Mukherjee R, Burn TC (May 2002). "Generation of multiple farnesoid-X-receptor isoforms through the use of alternative promoters". Gene 290 (1-2): 35–43.  
  • Pineda Torra I, Claudel T, Duval C, Kosykh V, Fruchart JC, Staels B (Feb 2003). "Bile acids induce the expression of the human peroxisome proliferator-activated receptor alpha gene via activation of the farnesoid X receptor". Molecular Endocrinology 17 (2): 259–72.  
  • Anisfeld AM, Kast-Woelbern HR, Meyer ME, Jones SA, Zhang Y, Williams KJ, Willson T, Edwards PA (May 2003). "Syndecan-1 expression is regulated in an isoform-specific manner by the farnesoid-X receptor". The Journal of Biological Chemistry 278 (22): 20420–8.  
  • Pircher PC, Kitto JL, Petrowski ML, Tangirala RK, Bischoff ED, Schulman IG, Westin SK (Jul 2003). "Farnesoid X receptor regulates bile acid-amino acid conjugation". The Journal of Biological Chemistry 278 (30): 27703–11.  
  • Zhao A, Lew JL, Huang L, Yu J, Zhang T, Hrywna Y, Thompson JR, de Pedro N, Blevins RA, Peláez F, Wright SD, Cui J (Aug 2003). "Human kininogen gene is transactivated by the farnesoid X receptor". The Journal of Biological Chemistry 278 (31): 28765–70.  
  • Barbier O, Torra IP, Sirvent A, Claudel T, Blanquart C, Duran-Sandoval D, Kuipers F, Kosykh V, Fruchart JC, Staels B (Jun 2003). "FXR induces the UGT2B4 enzyme in hepatocytes: a potential mechanism of negative feedback control of FXR activity". Gastroenterology 124 (7): 1926–40.  
  • Holt JA, Luo G, Billin AN, Bisi J, McNeill YY, Kozarsky KF, Donahee M, Wang DY, Mansfield TA, Kliewer SA, Goodwin B, Jones SA (Jul 2003). "Definition of a novel growth factor-dependent signal cascade for the suppression of bile acid biosynthesis". Genes & Development 17 (13): 1581–91.  
  • Claudel T, Inoue Y, Barbier O, Duran-Sandoval D, Kosykh V, Fruchart J, Fruchart JC, Gonzalez FJ, Staels B (Aug 2003). "Farnesoid X receptor agonists suppress hepatic apolipoprotein CIII expression". Gastroenterology 125 (2): 544–55.  
  • Hsiao PW, Fryer CJ, Trotter KW, Wang W, Archer TK (Sep 2003). "BAF60a mediates critical interactions between nuclear receptors and the BRG1 chromatin-remodeling complex for transactivation". Molecular and Cellular Biology 23 (17): 6210–20.  
  • Ryan KK, Tremaroli V, Clemmensen C, Kovatcheva-Datchary P, Myronovych A, Karns R, Wilson-Pérez HE, Sandoval DA, Kohli R, Bäckhed F, Seeley RJ (May 2014). "FXR is a molecular target for the effects of vertical sleeve gastrectomy". Nature 509 (7499): 183–8.  

External links

  • "Farnesoid X Receptor (NR1H4)". Nuclear Receptor Resource. 
  • farnesoid X-activated receptor at the US National Library of Medicine Medical Subject Headings (MeSH)