thyrotropin-releasing hormone receptor binding

Definition

Target type: molecularfunction

Binding to a receptor for thyrotropin-releasing hormone, a tripeptide hormone that is produced by the hypothalamus and stimulates the release of thyroid-stimulating hormone (TSH) and prolactin by the anterior pituitary. [PMID:8592728]

Thyrotropin-releasing hormone receptor (TRHR) binding is a crucial step in the hypothalamic-pituitary-thyroid (HPT) axis, a complex regulatory system that maintains thyroid hormone levels in the body. TRHR, a G protein-coupled receptor (GPCR), is expressed primarily in the anterior pituitary gland. The binding of thyrotropin-releasing hormone (TRH) to TRHR triggers a cascade of intracellular signaling events, ultimately leading to the release of thyroid-stimulating hormone (TSH).

TRH, a tripeptide, binds to the extracellular domain of TRHR, inducing a conformational change in the receptor. This conformational change activates the intracellular G protein, specifically the Gq/11 subtype. Activation of Gq/11 leads to the activation of phospholipase C (PLC), an enzyme that hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol trisphosphate (IP3). DAG activates protein kinase C (PKC), while IP3 triggers the release of calcium ions (Ca2+) from intracellular stores.

The increased intracellular Ca2+ levels, along with PKC activation, stimulate the synthesis and release of TSH from the pituitary gland. TSH, in turn, acts on the thyroid gland, stimulating the production and release of thyroid hormones, thyroxine (T4) and triiodothyronine (T3). These hormones play vital roles in regulating metabolism, growth, and development.

Therefore, TRHR binding is essential for the proper functioning of the HPT axis. It initiates a signaling pathway that ultimately leads to the release of thyroid hormones, which are crucial for maintaining homeostasis in the body.'
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Proteins (1)

Compounds (3)