Nuclear receptors: nomenclature, ligands, mechanisms of their effects on gene expression.

Nuclear receptors are DNA binding transcription factors possessing conservative domain organization. Their activity is regulated by lipophilic ligands, phosphorylation, and by interactions with other proteins. This review highlights the nomenclature of 1999 for human nuclear receptors and the ligand structure and domain organization of these receptors. The review also summarizes recent data on the structure of hormone response elements of specific genes, the structure-functional organization of receptor co-regulators (coactivators and corepressors). They mediate their effects on transcription via two main mechanisms: chromatin remodeling and the effect on the main transcriptional factors. Some attention is focused on specific features of signal transduction at negative hormone-response elements, regulation of receptor activity via phosphorylation, mechanisms of receptor cycle termination, and on physiological and biochemical properties of certain groups of receptors and processes that they regulate.