thyrotropin-releasing hormone receptor activity

Definition

Target type: molecularfunction

Combining with thyrotropin-releasing hormone to initiate a change in cell activity. [GOC:mah]

Thyrotropin-releasing hormone receptor (TRHR) activity is a crucial component of the hypothalamic-pituitary-thyroid (HPT) axis, regulating thyroid hormone production and release. The TRHR, a G protein-coupled receptor (GPCR), is expressed primarily in the anterior pituitary gland, where it binds to thyrotropin-releasing hormone (TRH), a tripeptide neurohormone.

Upon TRH binding, the TRHR undergoes conformational changes, activating its associated G protein, specifically Gq. This activation initiates a signaling cascade, involving the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) by phospholipase C (PLC) to generate inositol trisphosphate (IP3) and diacylglycerol (DAG).

IP3 mobilizes intracellular calcium (Ca2+) from the endoplasmic reticulum, leading to increased Ca2+ levels in the cytoplasm. DAG, in turn, activates protein kinase C (PKC), which phosphorylates various downstream targets, including transcription factors.

This intricate signaling pathway ultimately leads to the synthesis and release of thyroid-stimulating hormone (TSH) from the pituitary gland. TSH then travels to the thyroid gland, stimulating the production and release of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), which regulate numerous physiological processes, including metabolism, growth, and development.

Therefore, TRHR activity plays a vital role in the regulation of the HPT axis, ensuring adequate levels of thyroid hormones are maintained for optimal organismal function.'
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Proteins (1)

Compounds (1)