Identification and evaluation of constitutively active thyroid stimulating hormone receptor mutations

Area of Science:

• Endocrinology
• Molecular Biology
• Genetics

Background:

• The thyroid stimulating hormone receptor (TSHR) is a G protein-coupled receptor regulating thyroid gland function.
• TSHR activation is typically mediated by thyroid stimulating hormone (TSH); however, mutations can lead to constitutive activity.
• Constitutively active TSHR mutations are frequently found in the serpentine region, particularly the third intracellular loop or transmembrane domain six.

Purpose of the Study:

• To describe simple and cost-effective laboratory methods for studying TSHR constitutive mutations.
• To investigate the molecular mechanisms and functional consequences of TSHR activating mutations.

Main Methods:

• Screening TSHR gene mutations in paraffin-embedded thyroid tissue.
• In vitro measurement of TSHR constitutive activity.
• Flow cytometry analysis for cell surface TSHR expression.
• Analysis of TSH binding to TSHR.
• TSHR phosphorylation assays.

Main Results:

• The study presents a suite of accessible methods for TSHR mutation analysis.
• These methods allow for the comprehensive study of TSHR constitutive activity, expression, ligand binding, and phosphorylation.

Conclusions:

• The described methods provide a practical approach to investigating the genetic and functional aspects of TSHR mutations.
• These techniques facilitate the study of thyroid diseases associated with constitutively active TSHR.