Cellular factors which modulate hormone responses: glucocorticoid action in perspective.

Virtually all glucocorticoid effects are mediated through changes in gene transcription. Steroid binding to the receptor and nuclear binding of the steroid-receptor complex are pivotal events in this process, but may be modified by the ability of a given steroid to traverse the cell membrane or cause receptor activation. The physical nature of the receptor, its precise subcellular location, and the process by which gene activation is accomplished are unknown. Preparation of purified receptor and further characterization of the nuclear binding sites will be crucial to a better understanding of this process.