Part:BBa_K3522008

RXRα

BBa_K3522008 is a protein domain of retinoid X receptor α (RXRα), which forms a heterodimer with farnesoid X receptor α (FXRα) to modulate the expression of its target genes.

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal BamHI site found at 705
  Illegal BamHI site found at 858
  Illegal BamHI site found at 972
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 1270
  Illegal AgeI site found at 558
  
• 1000
  COMPATIBLE WITH RFC[1000]

Part BBa_K35220008 is one of the basic parts of Part BBa_K3522013

Contribution

Biology Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily. Its typical functional domains include DNA binding domain and ligand binding domain. After binding its ligand, FXR forms a heterodimer with another nuclear receptor retinoid X receptor, and then the receptor dimer binds to the FXR response element (FXRE) located in the promoter region of the FXR target gene, thereby, regulating the transcription of these genes.

Engineering Success

Transactivation of FXRE by FXR-RXRα complex Part BBa_K3522013 consists of a FXRE fragment and luciferase gene. When presence of FXR and RXRα, the FXRE is activated, subsequently, the luciferase gene is transcribed. Such a transactivation assay cam be used to verify the antagonistic effect of H7 on FXR. Finally, transactivation assay was further carried out to verify the antagonistic effect of H7 on FXR. As shown in Figure 3, FXR agonist GW4064 efficiently activated reporter gene expression, and H7 antagonized GW4064-induced reporter gene stimulation in transactivation assay. Thus, these results confirmed the antagonism of H7 against FXR transactivation activity.

Figure 1

                            Figure 1. H7 as an FXR antagonist inhibited transactivation activity.

HEK293T cells were transiently transfected with pcDNA3.1a-FXR, pcDNA3.1a-RXRα, pGL3-FXRE-Luc and pRL-SV40. After 6 h, cells were treated with different concentrations of H7 with GW4064 for 24 h. Then transactivation activity of FXR was detected by luciferase reporter assay. GW4064: FXR agonist, GS: FXR antagonist. All data were presented as mean ± S.E.M (*P<0.05, **P< 0.01, ***P< 0.001).