2019 Volume 31 Issue 179 Pages E49-E52
Protein O-glucosylation is a class of post-translational modifications that is enzymatically biosynthesized on epidermal growth-factor-like (EGF) repeats of proteins including Notch receptors. Attached to a distinct serine residue within the consensus sequence C1-X-S-X-(P/A)-C2 of EGF repeats, an O-linked glucose (Glc) can be extended by the addition of two xylose (Xyl) residues, forming a linear trisaccharide structure: Xylα1-3Xylα1-3Glcβ1-O-serine residue. A protein O-glucosyltransferase 1 (POGLUT1, Rumi in Drosophila) catalyzes the addition of O-Glc to EGF repeats in the endoplasmic reticulum. POGLUT1/rumi is essential for full Notch activity in mammals and Drosophila. Recent studies have found that mutations in POGLUT1 are linked to human diseases such as Dowling-Degos Disease and a new class of muscular dystrophy.