Structure, function and regulation of gonadotropin receptors - a perspective

Area of Science:

• Reproductive biology
• Molecular endocrinology
• Cell signaling

Background:

• Luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) are critical for reproductive functions.
• Recent advancements have illuminated the structure, activation, and expression regulation of these receptors.

Purpose of the Study:

• To provide an overview of current knowledge on LHR and FSHR structure, activation, and expression.
• To detail recent findings on the post-transcriptional regulation of LHR expression.

Main Methods:

• Electrophoretic gel mobility shift assay to identify LRBP.
• Purification of LRBP and characterization of its binding site on LHR mRNA.
• Investigation of signaling pathways (cAMP/PKA, ERK) involved in LRBP regulation.

Main Results:

• LRBP, an LH receptor mRNA binding protein, was identified in downregulated ovaries.
• LRBP expression increases via cAMP/PKA and ERK pathways during ligand-induced downregulation.
• LRBP binds LHR mRNA, forming an untranslatable complex that targets mRNA for degradation, reducing LHR mRNA and cell surface expression.

Conclusions:

• LRBP is a key mediator of post-transcriptional regulation of LHR expression.
• LRBP's mechanism involves mRNA binding, complex formation, and subsequent degradation.
• This pathway contributes to the downregulation of LHR levels in response to ligand stimulation.