What is the Origin of Steroid Receptor Complex?

This term is a foundational concept in molecular endocrinology, combining 'steroid' (the class of lipid-soluble hormones) and 'receptor complex' (the hormone-protein binding unit). The concept is rooted in the early 1960s with the discovery of intracellular receptors that mediate the actions of these lipid-soluble messengers. It represents a fundamental paradigm of gene regulation in human physiology.

What is the Mechanism of Steroid Receptor Complex?

The mechanism involves the lipophilic steroid hormone diffusing across the cell membrane and binding to the receptor protein, which is often chaperoned by heat shock proteins in the cytoplasm. Upon binding, the receptor undergoes a conformational change, shedding its chaperones and exposing a DNA-binding domain. The activated complex then moves into the nucleus, binds to specific hormone response elements (HREs) on the DNA, and either initiates or represses the transcription of target genes, thereby altering the cell's protein synthesis and function.

Steroid Receptor Complex ∞ Area

Steroid Receptor Complex

Meaning

A molecular structure formed when a steroid hormone, such as testosterone, estrogen, or cortisol, binds to its specific intracellular receptor protein, typically located in the cytoplasm or nucleus of a target cell. The formation of this complex is the crucial step that activates the receptor, enabling it to translocate to the nucleus and directly modulate gene transcription. This complex is the primary mediator of the steroid hormone’s powerful and long-lasting genomic effects.