title: Chaperone activity of protein O-fucosyltransferase 1 promotes notch receptor folding.
abstract: Notch proteins are receptors for a conserved signaling pathway that affects numerous cell fate decisions. We found that in Drosophila, Protein O-fucosyltransferase 1 (OFUT1), an enzyme that glycosylates epidermal growth factor-like domains of Notch, also has a distinct Notch chaperone activity. OFUT1 is an endoplasmic reticulum protein, and its localization was essential for function in vivo. OFUT1 could bind to Notch, was required for the trafficking of wild-type Notch out of the endoplasmic reticulum, and could partially rescue defects in secretion and ligand binding associated with Notch point mutations. This ability of OFUT1 to facilitate folding of Notch did not require its fucosyltransferase activity. Thus, a glycosyltransferase can bind its substrate in the endoplasmic reticulum to facilitate normal folding.
authors.affiliation: Howard Hughes Medical Institute, Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Okajima
authors.forename: Aiguo
authors.initials: A
authors.lastname: Xu
authors.forename: Liang
authors.initials: L
authors.lastname: Lei
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Irvine
mesh_terms: D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005643:Fucose / Q000378:metabolism; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006154:Guanosine Diphosphate Fucose / Q000378:metabolism; D008024:Ligands; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018832:Molecular Chaperones / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding; D017510:Protein Folding; D021381:Protein Transport; D034622:RNA Interference; D051880:Receptors, Notch; D011994:Recombinant Proteins / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D029721:Drosophila Proteins; D008024:Ligands; D008565:Membrane Proteins; D018832:Molecular Chaperones; C497759:N protein, Drosophila; D051880:Receptors, Notch; D011994:Recombinant Proteins; D006154:Guanosine Diphosphate Fucose; D005643:Fucose; D005647:Fucosyltransferases; C471275:O-fucosyltransferase 1, Drosophila