PMID: 15723037 , Related PDB id: 1YUC

Authors:

Ortlund EA, Lee Y, Solomon IH, Hager JM, Safi R, Choi Y, Guan Z, Tripathy A, Raetz CR, McDonnell DP, Moore DD, Redinbo MR

Title:

Modulation of human nuclear receptor LRH-1 activity by phospholipids and SHP.

Journal:

Nat Struct Mol Biol. 2005 Apr;12(4):357-63. Epub 2005 Feb 22.

Abstract:

The human nuclear receptor liver receptor homolog 1 (hLRH-1) plays an important role in the development of breast carcinomas. This orphan receptor is efficiently downregulated by the unusual co-repressor SHP and has been thought to be ligand-independent. We present the crystal structure at a resolution of 1.9 A of the ligand-binding domain of hLRH-1 in complex with the NR box 1 motif of human SHP, which we find contacts the AF-2 region of hLRH-1 using selective structural motifs. Electron density indicates phospholipid bound within the ligand-binding pocket, which we confirm using mass spectrometry of solvent-extracted samples. We further show that pocket mutations reduce phospholipid binding and receptor activity in vivo. Our results indicate that hLRH-1's control of gene expression is mediated by phospholipid binding, and establish hLRH-1 as a novel target for compounds designed to slow breast cancer development.