Posttranslational Modification of Thyroid Hormone Nuclear Receptor by Sumoylation.

Thyroid hormone has a broad range of biological effects, both during development and in the adult. Nuclear thyroid hormone action is mediated by thyroid hormone receptor (TR) α and β. Thyroid hormone also has nongenomic actions at the membrane, which are less well characterized. Both TRα and TRβ undergo posttranslational modification, including phosphorylation, acetylation, and recently identified sumoylation. These posttranslational modifications have been shown to influence thyroid hormone signaling by altering TR DNA binding, TR interaction with cofactors, and TR-mediated transcription. The best characterized modification, with respect to gene regulation, is sumoylation, which plays an important role in nutrient regulators-mediated gene expression. We present an approach to study posttranslational modification of TR by small ubiquitin-like modifier (SUMO), a process referred to as sumoylation.