Regulation of Receptor Expression: Analysis of Receptor mRNA and Gene Transcription

In addition to desensitization and downregulation of receptors at the cell membrane, the number of receptors expressed is modulated by regulation of steady-state levels of mRNA and the rate of gene transcription (see refs. 1 and 2 for reviews). Regulation of receptor mRNA and gene transcription has been observed for many different types of receptors, including those for hormones, neurotransmitters, and neuropepitdes, and may occur in response to exposure to receptor agonists, different types of hormones, or drug treatments (3 –9 ). Thus, regulation of receptor mRNA and gene transcription could represent a mechanism for long-term modulation of receptor expression.