2. Academic Validation
  3. Molecular basis for fibroblast growth factor 23 O-glycosylation by GalNAc-T3

Molecular basis for fibroblast growth factor 23 O-glycosylation by GalNAc-T3

  • Nat Chem Biol. 2020 Mar;16(3):351-360. doi: 10.1038/s41589-019-0444-x.
Matilde de Las Rivas # 1,  Earnest James Paul Daniel # 2,  Yoshiki Narimatsu # 3,  Ismael Compañón # 4,  Kentaro Kato 3 5,  Pablo Hermosilla 6,  Aurélien Thureau 7,  Laura Ceballos-Laita 1,  Helena Coelho 8 9,  Pau Bernadó 10,  Filipa Marcelo 8,  Lars Hansen 3,  Ryota Maeda 11,  Anabel Lostao 6 12 13,  Francisco Corzana 4,  Henrik Clausen 3,  Thomas A Gerken 2,  Ramon Hurtado-Guerrero 14 15 16
Affiliations

Affiliations

  • 1 BIFI, University of Zaragoza, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza, Spain.
  • 2 Department of Biochemistry, Case Western Reserve University, Cleveland, OH, USA.
  • 3 Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, Copenhagen, Denmark.
  • 4 Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, Logroño, Spain.
  • 5 Department of Eco-epidemiology, Institute of Tropical Medicine Nagasaki University, Nagasaki, Japan.
  • 6 Laboratorio de Microscopías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Zaragoza, Spain.
  • 7 Swing Beamline, Synchrotron SOLEIL, Gif sur Yvette, France.
  • 8 UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade de Nova de Lisboa, Caparica, Portugal.
  • 9 CIC bioGUNE, Bizkaia Technology Park, Derio, Spain.
  • 10 Centre de Biochimie Structurale. INSERM, CNRS, Université de Montpellier, Montpellier, France.
  • 11 Department of Hematology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
  • 12 Fundación ARAID, Zaragoza, Spain.
  • 13 Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Zaragoza, Spain.
  • 14 BIFI, University of Zaragoza, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza, Spain. rhurtado@bifi.es.
  • 15 Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, Copenhagen, Denmark. rhurtado@bifi.es.
  • 16 Fundación ARAID, Zaragoza, Spain. rhurtado@bifi.es.
  • # Contributed equally.
PMID: 31932717 DOI: 10.1038/s41589-019-0444-x
Abstract

Polypeptide GalNAc-transferase T3 (GalNAc-T3) regulates Fibroblast Growth Factor 23 (FGF23) by O-glycosylating Thr178 in a Furin proprotein processing motif RHT178R↓S. FGF23 regulates phosphate homeostasis and deficiency in GALNT3 or FGF23 results in hyperphosphatemia and familial tumoral calcinosis. We explored the molecular mechanism for GalNAc-T3 glycosylation of FGF23 using engineered cell models and biophysical studies including kinetics, molecular dynamics and X-ray crystallography of GalNAc-T3 complexed to Glycopeptide substrates. GalNAc-T3 uses a lectin domain mediated mechanism to glycosylate Thr178 requiring previous glycosylation at Thr171. Notably, Thr178 is a poor substrate site with limiting glycosylation due to substrate clashes leading to destabilization of the catalytic domain flexible loop. We suggest GalNAc-T3 specificity for FGF23 and its ability to control circulating levels of intact FGF23 is achieved by FGF23 being a poor substrate. GalNAc-T3's structure further reveals the molecular bases for reported disease-causing mutations. Our findings provide an insight into how GalNAc-T isoenzymes achieve isoenzyme-specific nonredundant functions.

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