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Updated: Jul 3, 2026
10:09
Detection of Detergent-sensitive Interactions Between Membrane Proteins
Published on: March 7, 2018
Sortilin is a putative postendocytic receptor of thyroglobulin
Roberta Botta1, Simonetta Lisi, Aldo Pinchera
1Department of Endocrinology, University of Pisa, Via Paradisa 2, 56124, Pisa, Italy.
Endocrinology
|August 9, 2008
Summary
Sortilin, a protein involved in cell trafficking, is expressed in thyroid cells and binds thyroglobulin (Tg). This interaction, occurring after Tg endocytosis, facilitates Tg recycling, revealing a new role for sortilin in thyroid hormone regulation.
Area of Science:
- Cell Biology
- Endocrinology
- Molecular Biology
Background:
- Sortilin (Vps10p family) is known for its role in protein trafficking.
- Thyroid epithelial cells (thyrocytes) produce thyroglobulin (Tg), the precursor for thyroid hormones.
Purpose of the Study:
- To investigate the role of sortilin in thyrocyte function.
- To determine if sortilin interacts with thyroglobulin (Tg) and influences its trafficking.
Main Methods:
- Immunofluorescence and immunoelectron microscopy to visualize intracellular localization and interaction.
- Plasmon resonance binding assays to quantify Tg-sortilin affinity.
- Gene silencing (siRNA) to assess the functional impact of sortilin on Tg recycling.
- Immunoprecipitation to confirm in vivo and in vitro interactions.
Main Results:
- Sortilin is expressed intracellularly in thyrocytes from multiple species and cell lines.
- Sortilin expression is dependent on thyroid-stimulating hormone (TSH).
- Thyroglobulin (Tg) binds to sortilin with high affinity, and this interaction occurs after Tg endocytosis, promoting Tg recycling.
Conclusions:
- Sortilin plays a novel role in the thyroid gland by mediating thyroglobulin (Tg) trafficking and recycling.
- The TSH-dependent expression of sortilin suggests its involvement in regulating thyroid hormone precursor availability.
- Further research is needed to establish the full functional impact of sortilin in thyrocytes.
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