Title :

Assembly of the respiratory mucin MUC5B: a new model for a gel-forming mucin.

Author(s) :

Ridley, Caroline [Auteur]
Kouvatsos, Nikos [Auteur]
Raynal, Bertrand D [Auteur]
Howard, Marj [Auteur]
Collins, Richard F [Auteur]
Desseyn, Jean-Luc [Auteur]
Lille Inflammation Research International Center - U 995 [LIRIC]
Jowitt, Thomas A [Auteur]
Baldock, Clair [Auteur]
Davis, C William [Auteur]
Hardingham, Timothy E [Auteur]
Thornton, David J [Auteur]

Journal title :

THE JOURNAL OF BIOLOGICAL CHEMISTRY

Abbreviated title :

J Biol Chem

Volume number :

289

Pages :

16409-20

Publication date :

2014-06-06

ISSN :

1083-351X

English keyword(s) :

Calcium
Hydrogen-Ion Concentration
Microscopy
Electron
Transmission
Mucin-5B
Respiratory System
Ultracentrifugation
Analytical Ultracentrifugation
Cystic Fibrosis
Goblet Cell
Mucin
Mucus
Recombinant Protein Expression
Single Particle Analysis

HAL domain(s) :

Sciences du Vivant [q-bio]

English abstract : [en]

Mucins are essential components in mucus gels that form protective barriers at all epithelial surfaces, but much remains unknown about their assembly, intragranular organization, and post-secretion unfurling to form mucus. ...
Show more >Mucins are essential components in mucus gels that form protective barriers at all epithelial surfaces, but much remains unknown about their assembly, intragranular organization, and post-secretion unfurling to form mucus. MUC5B is a major polymeric mucin expressed by respiratory epithelia, and we investigated the molecular mechanisms involved during its assembly. Studies of intact polymeric MUC5B revealed a single high affinity calcium-binding site, distinct from multiple low affinity sites on each MUC5B monomer. Self-diffusion studies with intact MUC5B showed that calcium binding at the protein site catalyzed reversible cross-links between MUC5B chains to form networks. The site of cross-linking was identified in the MUC5B D3-domain as it was specifically blocked by D3 peptide antibodies. Biophysical analysis and single particle EM of recombinant MUC5B N terminus (D1D2D'D3; NT5B) and subdomains (D1, D1-D2, D2-D'-D3, and D3) generated structural models of monomers and disulfide-linked dimers and suggested that MUC5B multimerizes by disulfide linkage between D3-domains to form linear polymer chains. Moreover, these analyses revealed reversible homotypic interactions of NT5B at low pH and in high calcium, between disulfide-linked NT5B dimers, but not monomers. These results enable a model of MUC5B to be derived, which predicts mechanisms of mucin intracellular assembly and storage, which may be common to the other major gel-forming polymeric mucins.Show less >

Language :

Anglais

Audience :

Non spécifiée

Collections :

• Institut de Recherche Translationnelle sur l'Inflammation (INFINITE) - U1286

Submission date :

2019-07-09T13:57:45Z
2019-07-10T07:02:17Z