Final answer:
Cortisol, a glucocorticoid hormone involved in stress response, passes into cells and binds to glucocorticoid receptors. This complex then binds to DNA regulatory elements, regulating the transcription of specific genes to alter protein synthesis and affect various cellular functions.
Step-by-step explanation:
The steroid hormone cortisol is a glucocorticoid involved in the body's response to stress. It acts by diffusing across the cell membrane and binding to glucocorticoid receptors, which are intracellular proteins capable of moving into the nucleus. Once bound to cortisol, the receptor can enter the nucleus and bind to glucocorticoid response elements (GRE) in the DNA, which are regulatory sequences controlling gene transcription. This complex acts as a transcription factor, either upregulating or downregulating the expression of specific genes. The result is an increase or decrease in the synthesis of particular proteins, impacting processes such as glucose metabolism, immune response, and fatty acid mobilization.
During long-term stress, for instance, the hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the anterior pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH, in turn, prompts the adrenal cortex to produce and release cortisol. The cortisol then travels to target cells, executing the aforementioned steps to alter cellular functions necessary for managing stress over extended periods.