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Updated: Aug 11, 2026
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Detection of Ligand-activated G Protein-coupled Receptor Internalization by Confocal Microscopy
Published on: April 9, 2017
Biglycan is internalized via a chlorpromazine-sensitive route
Martin Götte1, David Denis Sofeu Feugaing, Hans Kresse
1Department of Physiological Chemistry, Münster University Hospital, Domagkstr. 11, D-48149 Münster, Germany. mgotte@uni-muenster.de
Cellular & Molecular Biology Letters
|August 28, 2004
Summary
Biglycan (BGN) internalization in fibroblasts primarily occurs via clathrin-mediated endocytosis. This pathway significantly impacts BGN degradation, suggesting a key role in regulating extracellular matrix proteoglycan levels.
Area of Science:
- Biochemistry
- Cell Biology
- Extracellular Matrix Biology
Background:
- Biglycan (BGN) is a small leucine-rich proteoglycan crucial in mesenchymal tissues.
- BGN expression levels correlate with cellular differentiation and are dysregulated in various diseases.
- Extracellular BGN concentration is controlled by both secretion and endocytosis.
Purpose of the Study:
- To investigate the mechanisms of biglycan (BGN) endocytosis in human skin fibroblasts.
- To identify the specific endocytic pathways involved in BGN internalization and degradation.
Main Methods:
- Utilized in vitro studies with human skin fibroblasts.
- Employed pharmacological inhibitors targeting distinct endocytic pathways (clathrin-mediated, caveolae).
- Assessed the impact of inhibitors on BGN internalization and degradation rates.
Main Results:
- Chlorpromazine (clathrin inhibitor) reduced BGN endocytosis by 40% and degradation by 66%.
- Filipin (caveolae inhibitor) and Tyrphostin AG 1478 (EGFR inhibitor) did not affect BGN uptake or degradation.
- BGN endocytosis appears mechanistically distinct from decorin uptake.
Conclusions:
- Clathrin-mediated endocytosis is the predominant pathway for BGN internalization in human skin fibroblasts.
- BGN uptake and degradation are significantly influenced by the clathrin pathway.
- The endocytic mechanism for BGN differs from that of decorin.
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