In the endoplasmic reticulum, glycosyl transferases modify NOTCH precursors by glycosylating conserved serine and threonine residues in EGF repeats of NOTCH.
O-fucosyl transferase POFUT1 fucosylates NOTCH serine and threonine residues that conform to the consensus sequence C2-X(4-5)-S/T-C3, where C2 and C3 are the second and third cysteine residue within the EGF repeat, and X(4-5) is four to five amino acid residues of any type (Yao et al. 2011, Stahl et al. 2008, Wang et al. 2001, Shao et al. 2003).
O-glucosyl transferase POGLUT1, mammalian homolog of the Drosophila enzyme Rumi, adds a glucosyl group to conserved serine residues within the EGF repeats of NOTCH. The consensus sequence for POGLUT1-mediated glucosylation is C1-X-S-X-P-C2, where C1 and C2 are the first and second cysteine residue in the EGF repeat, respectively, while X represents any amino acid (Acar et al. 2008, Fernandez-Valdivia et al. 2011). Both fucosylation and glucosylation of NOTCH receptor precursors are essential for functionality.
|21464368||Protein O-fucosyltransferase 1 (Pofut1) regulates lymphoid and myeloid homeostasis through modulation of Notch receptor ligand interactions||Blood||2011|
|18347015||Roles of Pofut1 and O-fucose in mammalian Notch signaling||J Biol Chem||2008|
|11524432||Modification of epidermal growth factor-like repeats with O-fucose. Molecular cloning and expression of a novel GDP-fucose protein O-fucosyltransferase||J Biol Chem||2001|
|12486116||Fringe modifies O-fucose on mouse Notch1 at epidermal growth factor-like repeats within the ligand-binding site and the Abruptex region||J Biol Chem||2003|
|18243100||Rumi is a CAP10 domain glycosyltransferase that modifies Notch and is required for Notch signaling||Cell||2008|
|21490058||Regulation of mammalian Notch signaling and embryonic development by the protein O-glucosyltransferase Rumi||Development||2011|