CHAPTER 279 – Orphan Receptor COUP-TFII and Vascular Development

Nuclear receptors belong to a large family of transcription factors, which can modulate gene expression. Since the discovery of the steroid/thyroid hormone receptor superfamily, an increasing number of transcription factors with similar structural motif have been added. A majority of these newly added members have unknown ligands, thus they are classified as orphan nuclear receptors. Like the other members of the steroid/thyroid hormone receptor superfamily, the orphan receptors are involved in development, differentiation, and homeostasis processes. The absence of ligand makes it more difficult to dissect the functional role of orphan receptors. However, the analysis of orphan receptor null mice will provide new insights into the physiological function of these receptors during development, organogenesis, and homeostasis. This chapter attempts to describe the functional role of orphan receptors during vascular development.