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Evaluation of Substrate Ubiquitylation by E3 Ubiquitin-ligase in Mammalian Cell Lysates
Published on: May 10, 2022
Using a ubiquitin ligase as an unfolded protein sensor
Adam Mallinger1, Hsiang M Wen, Geoffrey M Dankle
1Kansas City University of Medicine and Biosciences, Kansas City, MO 64106, USA.
Biochemical and Biophysical Research Communications
|January 10, 2012
Summary
FBXO2 protein binds unfolded glycoproteins, acting as a sensor for cellular stress. This discovery aids in understanding protein quality control and endoplasmic reticulum-associated degradation (ERAD) pathways.
Area of Science:
- Biochemistry
- Molecular Biology
- Cellular Homeostasis
Background:
- Misfolded proteins are a significant cellular burden, necessitating degradation pathways.
- The ubiquitin-proteasome system and endoplasmic reticulum-associated degradation (ERAD) are crucial for protein quality control.
- High-mannose glycans mark misfolded glycoproteins for ERAD.
Purpose of the Study:
- To investigate the binding preferences of FBXO2.
- To determine FBXO2's role in recognizing unfolded glycoproteins.
- To establish FBXO2 as a potential sensor for misfolded glycoproteins.
Main Methods:
- Utilized glycan arrays and immobilized glycoprotein pulldowns.
- Performed glycan competition assays.
- Employed recombinant GST-FBXO2 as an unfolded protein sensor.
Main Results:
- FBXO2 demonstrates preferential binding to unfolded glycoproteins.
- FBXO2 can be used as a sensor to detect increased misfolded glycoproteins.
- This binding is linked to high-mannose glycan recognition.
Conclusions:
- FBXO2 preferentially binds unfolded glycoproteins, particularly those with high-mannose glycans.
- Recombinant FBXO2 serves as a valuable sensor for monitoring ER stress and misfolded protein accumulation.
- FBXO2 plays a role in the ERAD pathway for glycoprotein quality control.
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