Loss of core-fucosylation of SPARC impairs collagen binding and contributes to COPD.
Tsai-Jung WuSheng-Hung WangEric Sheng-Wen ChenHsiu-Hui TsaiYi-Chieh ChangYi-Hsin TsengJohn YuPublished in: Cellular and molecular life sciences : CMLS (2022)
Chronic obstructive pulmonary disease (COPD) is a progressive lung disease with high morbidity and mortality worldwide. Although several mechanisms to account for deleterious immune effects were proposed, molecular description for the underlying alveolar structural alterations for COPD is lacking. Here, silencing of α1,6-fucosyltransferase (Fut8), the enzyme for core-fucosylation and highly expressed in lung stem cells, resulted in alveolar structural changes in lung organoids, recapitulating COPD. Site-specific mass spectrometry analysis demonstrated that the secreted protein acidic and rich in cysteine (SPARC), which binds collagen, contains a core-fucosylation site in its VCSNDN cf K glycopeptide. Biacore assay showed markedly reduced collagen binding of SPARC lacking core fucosylation. Molecular dynamics analysis revealed that core fucosylation of SPARC-induced dynamic conformational changes in its N-glycan, allowing terminal galactose and N-acetylglucosamine to interact with K150, P261 and H264 residues, thereby promoting collagen binding. Site-specific mutagenesis of these residues also resulted in low affinity for collagen binding. Moreover, loss of collagen and decline of core fucosylation were observed in COPD lung tissues. These findings provide a new mechanistic insight into the role of core fucosylation of SPARC in cell-matrix communication and contribution to the abnormal alveolar structures in COPD.
Keyphrases
- chronic obstructive pulmonary disease
- lung function
- molecular dynamics
- stem cells
- mass spectrometry
- tissue engineering
- cystic fibrosis
- high resolution
- single cell
- dna binding
- gene expression
- density functional theory
- air pollution
- molecular dynamics simulations
- mesenchymal stem cells
- ms ms
- bone marrow
- diabetic rats
- simultaneous determination
- stress induced