Fig. 5: NR-box2 and box3 of the SRC1-NRID domain interact with FXR-RXRα heterodimer.
A Schematic diagram of mutations for different NR-boxes of SRC1 used in this study. B In the presence of GW4064 and 9cRA, BLI experiments were conducted to investigate the binding affinity of biotinylated SRC1630-987 and various NR-box mutants of SRC1630-987 with FXR120-RXRα98-hSHP-1. The calculated KD value is indicated on the right. C Luciferase reporter assay was used to test the effect of different mutants of the NR-box of SRC1 on FXR-RXRα promoting hSHP-1 transcription in the presence of GW4064 (100 nM in 0.1% DMSO) and 9cRA (100 nM in 0.1% DMSO). Data represents mean from n = 3 experiments, Error bars represent SEM, ns represent no significance (P > 0.05). ***P < 0.001, ****P < 0.0001. D High confidence (score ≥10) BS3 cross-linked residues shown on the sequence schematic of FXR and RXRα, with green lines representing cross-links and purple representing self-links. E Cross-linking between the NRID domain of SRC1 and FXR-RXRα is depicted in our model. The left side of the panel shows a schematic representation of the three NR-boxes in the NRID domain of SRC1, indicating the specific amino acids involved in cross-linking with FXR and RXRα. On the right, the residues in FXR-RXRα cross-linked to SRC1 were shown, and the connections were represented by red lines (FXR, pink; RXRα, slate).
