Conformation of the N-Terminal Ectodomain Elicits Different Effects on DUOX Function: A Potential Impact on Congenital Hypothyroidism Caused by a H 2 O 2 Production Defect

Ruy Andrade Louzada, Raphael Corre, Rabii Ameziane-El-Hassani, Fabio Hecht, Juliana Cazarin, Camille Buffet, Denise P. Carvalho, Corinne Dupuy

    Résultats de recherche: Contribution à un journalArticleRevue par des pairs

    10 Citations (Scopus)

    Résumé

    Background: Dual oxidases (DUOX1 and DUOX2) were initially identified as H 2 O 2 sources involved in thyroid hormone synthesis. Congenital hypothyroidism (CH) resulting from inactivating mutations in the DUOX2 gene highlighted that DUOX2 is the major H 2 O 2 provider to thyroperoxidase. The role of DUOX1 in the thyroid remains unknown. A recent study suggests that it could compensate for DUOX2 deficiency in CH. Both DUOX enzymes and their respective maturation factors DUOXA1 and DUOXA2 form a stable complex at the cell surface, which is fundamental for their enzymatic activity. Recently, intra- and intermolecular disulfide bridges were identified that are essential for the structure and the function of the DUOX2-DUOXA2 complex. This study investigated the involvement of cysteine residues conserved in DUOX1 toward the formation of disulfide bridges, which could be important for the function of the DUOX1DUOXA1 complex. Methods: To analyze the role of these cysteine residues in both the targeting and function of dual oxidase, different human DUOX1 mutants were constructed, where the cysteine residues were replaced with glycine. The effect of these mutations on cell surface expression and H 2 O 2 -generating activity of the DUOX1-DUOXA1 complex was analyzed. Results: Mutations of two cysteine residues (C118 and C1165), involved in the formation of the intramolecular disulfide bridge between the N-terminal ectodomain and one of the extracellular loops, mildly altered the function and the targeting of DUOX1, while this bridge is crucial for DUOX2 function. Unlike DUOXA2, with respect to DUOX2, the stability of the maturation factor DUOXA1 is not dependent on the oxidative folding of DUOX1. Only mutation of C579 induced a strong alteration of both targeting and function of the oxidase by preventing the covalent interaction between DUOX1 and DUOXA1. Conclusion: An intermolecular disulfide bridge rather than an intramolecular disulfide bridge is important for both the trafficking and H 2 O 2 -generating activity of the DUOX1-DUOXA1 complex.

    langue originaleAnglais
    Pages (de - à)1052-1062
    Nombre de pages11
    journalThyroid
    Volume28
    Numéro de publication8
    Les DOIs
    étatPublié - 1 août 2018

    Contient cette citation