Estrogen-receptor-related receptors and hormone-dependent cancers.

摘要

Nuclear receptors (NRs) comprise a superfamily of ligand-dependent transcription factors that all share similar modular structures. A highly conserved DNA-binding domain (DBD), located toward the center of the NR, mediates recognition of specific response elements (REs) within the promoters of target genes. The C-terminus contains a less conserved ligand-binding domain (LBD), which is responsible for ligand-recognition, homo- or hetero-dimerization, interaction with co-modulators, and activation of target gene transcription. A number of NRs, termed "orphan" receptors, display features similar to those found in the "classical" (i.e., "liganded") receptors, including a putative LBD, but for which no natural ligand has been characterized. Whether such ligands indeed exist, or whether orphan receptors can activate transcription in a constitutive manner is still subject to debate