Using a Ubiquitin Ligase as an Unfolded Protein Sensor
Document Type
Article
Publication Title
Biochemical and Biophysical Research Communications
Abstract
A significant fraction of all proteins are misfolded and must be degraded. The ubiquitin-proteasome pathway provides an essential protein quality control function necessary for normal cellular homeostasis. Substrate specificity is mediated by proteins called ubiquitin ligases. In the endoplasmic reticulum (ER) a specialized pathway, the endoplasmic reticulum associated degradation (ERAD) pathway provides means to eliminate misfolded proteins from the ER. One marker used by the ER to identify misfolded glycoproteins is the presence of a high-mannose (Man5-8GlcNAc2) glycan. Recently, FBXO2 was shown to bind high mannose glycans and participate in ERAD. Using glycan arrays, immobilized glycoprotein pulldowns, and glycan competition assays we demonstrate that FBXO2 preferentially binds unfolded glycoproteins. Using recombinant, bacterially expressed GST-FBXO2 as an unfolded protein sensor we demonstrate it can be used to monitor increases in misfolded glycoproteins after physiological or pharmaceutical stressors.
DOI
10.1016/j.bbrc.2011.12.109
Publication Date
2-3-2012
ISSN
1090-2104
Recommended Citation
Mallinger A, Wen HM, Dankle GM, Glenn KA. Using a Ubiquitin Ligase as an Unfolded Protein Sensor. Biochemical and Biophysical Research Communications. 2012; 418(1). doi: 10.1016/j.bbrc.2011.12.109.
