Multiple Isoforms of Thyroid Hormone Receptor: an Analysis of Their Relative Contribution in Mediating Thyroid Hormone Action

摘要: Thyroid hormone is essential for normal development and maintaining metabolic homeostasis. In mediating the thyroid action, receptor (TR) plays a key role. Almost one decade ago, cloning of TR was achieved, revealing existence at least two genes, alpha beta, which encode TR. From these genes several isoforms can be generated by alternative splicing. They are designated as 1, 2 (inactive form), beta 1 2. Since discovery isoforms, many studies have attempted to demonstrate their relative contribution mediate in various tissues. The distinct tissue distribution ontogenic expression fact that gene abnormalities associated with syndrome resistance (RTH) been found only gene, indicate products roles. However, no direct evidence roles has shown. Gene knockouts either isoform would provide important information understanding specific this review, history attempting summarized, recent reports dealing comprehensively presented.