O-GlcNAc on NOTCH1 EGF repeats regulates ligand-induced Notch signaling and vascular development in mammals
Shogo Sawaguchi,
Shweta Varshney,
Mitsutaka Ogawa,
Yuta Sakaidani,
Hirokazu Yagi,
Kyosuke Takeshita,
Toyoaki Murohara,
Koichi Kato,
Subha Sundaram,
Pamela Stanley,
Tetsuya Okajima
Affiliations
Shogo Sawaguchi
Department of Molecular Biochemistry, Nagoya University Graduate School of Medicine, Nagoya, Japan
Shweta Varshney
Department of Cell Biology, Albert Einstein College of Medicine, New York, United States
Mitsutaka Ogawa
Department of Molecular Biochemistry, Nagoya University Graduate School of Medicine, Nagoya, Japan
Yuta Sakaidani
Department of Molecular Biochemistry, Nagoya University Graduate School of Medicine, Nagoya, Japan
Hirokazu Yagi
Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
Kyosuke Takeshita
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
Toyoaki Murohara
Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
Koichi Kato
Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan; Institute for Molecular Science and Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Japan
Subha Sundaram
Department of Cell Biology, Albert Einstein College of Medicine, New York, United States
The glycosyltransferase EOGT transfers O-GlcNAc to a consensus site in epidermal growth factor-like (EGF) repeats of a limited number of secreted and membrane proteins, including Notch receptors. In EOGT-deficient cells, the binding of DLL1 and DLL4, but not JAG1, canonical Notch ligands was reduced, and ligand-induced Notch signaling was impaired. Mutagenesis of O-GlcNAc sites on NOTCH1 also resulted in decreased binding of DLL4. EOGT functions were investigated in retinal angiogenesis that depends on Notch signaling. Global or endothelial cell-specific deletion of Eogt resulted in defective retinal angiogenesis, with a mild phenotype similar to that caused by reduced Notch signaling in retina. Combined deficiency of different Notch1 mutant alleles exacerbated the abnormalities in Eogt−/− retina, and Notch target gene expression was decreased in Eogt−/−endothelial cells. Thus, O-GlcNAc on EGF repeats of Notch receptors mediates ligand-induced Notch signaling required in endothelial cells for optimal vascular development.
