Thyroid hormone receptor subtypes and their interaction with steroid receptor coactivators.

Thyroid hormone (TH) is required for normal growth, development, and metabolism in metazoans. To influence this broad range of physiologic actions, TH is necessarily involved in the regulation of a multitude of genes in virtually every tissue. The diversity of gene expression regulation in response to TH is mediated through specific intranuclear TH receptors (TRs) and other nuclear coregulators. This chapter reviews TRs and nuclear coregulators, specifically coactivators, based on in vivo data from knockout (KO) mouse models.