Title :
Quiescin sulfhydryl oxidase 1 (
QSOX1 )
glycosite mutation perturbs secretion but not Golgi localization
Abstract :
- Quiescin sulfhydryl oxidase 1 ( QSOX1 ) catalyzes the formation of disulfide bonds in protein substrates
- Unlike other enzymes with related activities, which are commonly found in the endoplasmic reticulum, QSOX1 is localized to the Golgi apparatus or secreted
- QSOX1 is upregulated in quiescent fibroblast cells and secreted into the extracellular environment, where it contributes to extracellular matrix assembly
- QSOX1 is also upregulated in adenocarcinomas, though the extent to which it is secreted in this context is currently unknown
- To achieve a better understanding of factors that dictate QSOX1 localization and function, we aimed to determine how post-translational modifications affect QSOX1 trafficking and activity
- We found a highly conserved N-linked glycosylation site to be required for QSOX1 secretion from fibroblasts and other cell types
- Notably, QSOX1 lacking a glycan at this site arrives at the Golgi, suggesting that it passes endoplasmic reticulum quality control but is not further transported to the cell surface for secretion
- The QSOX1 transmembrane segment is dispensable for Golgi localization and secretion, as fully luminal and transmembrane variants displayed the same trafficking behavior
- This study provides a key example of the effect of glycosylation on Golgi exit and contributes to an understanding of late secretory sorting and quality control
Output (sent_index, trigger,
protein,
sugar,
site):
- 0. glycosite, , -, -, glycosite
- 6. glycosylation, , -, -, site
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):