Faculty Collaboration Database

The importance of N-glycosylation on β₃ integrin ligand binding and conformational regulation. Sci Rep 2017 Jul 05;7(1):4656

Date

07/07/2017

Pubmed ID

28680094

Pubmed Central ID

PMC5498496

DOI

10.1038/s41598-017-04844-w

Scopus ID

2-s2.0-85021948659 (requires institutional sign-in at Scopus site)   46 Citations

Abstract

N-glycosylations can regulate the adhesive function of integrins. Great variations in both the number and distribution of N-glycosylation sites are found in the 18 α and 8 β integrin subunits. Crystal structures of α_IIbβ₃ and α_Vβ₃ have resolved the precise structural location of each N-glycan site, but the structural consequences of individual N-glycan site on integrin activation remain unclear. By site-directed mutagenesis and structure-guided analyses, we dissected the function of individual N-glycan sites in β₃ integrin activation. We found that the N-glycan site, β₃-N320 at the headpiece and leg domain interface positively regulates α_IIbβ₃ but not α_Vβ₃ activation. The β₃-N559 N-glycan at the β₃-I-EGF3 and α_IIb-calf-1 domain interface, and the β₃-N654 N-glycan at the β₃-β-tail and α_IIb-calf-2 domain interface positively regulate the activation of both α_IIbβ₃ and α_Vβ₃ integrins. In contrast, removal of the β₃-N371 N-glycan near the β₃ hybrid and I-EGF3 interface, or the β₃-N452 N-glycan at the I-EGF1 domain rendered β₃ integrin more active than the wild type. We identified one unique N-glycan at the βI domain of β₁ subunit that negatively regulates α₅β₁ activation. Our study suggests that the bulky N-glycans influence the large-scale conformational rearrangement by potentially stabilizing or destabilizing the domain interfaces of integrin.

Author List

Cai X, Thinn AMM, Wang Z, Shan H, Zhu J

Author

Jieqing Zhu PhD Assistant Professor, Associate Investigator in the Biochemistry department at BloodCenter of Wisconsin

MESH terms used to index this publication - Major topics in bold

Binding Sites
Glycosylation
HEK293 Cells
Humans
Integrin alphaVbeta3
Integrin beta3
Ligands
Mitochondrial Proteins
Models, Molecular
Mutagenesis, Site-Directed
Peptide Elongation Factor G
Platelet Glycoprotein GPIIb-IIIa Complex
Polysaccharides
Protein Binding
Protein Conformation