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O-fucosylation of the notch ligand mDLL1 by POFUT1 is dispensable for ligand function.

Authors :
Julia Müller
Nadia A Rana
Katrin Serth
Shinako Kakuda
Robert S Haltiwanger
Achim Gossler
Source :
PLoS ONE, Vol 9, Iss 2, p e88571 (2014)
Publication Year :
2014
Publisher :
Public Library of Science (PLoS), 2014.

Abstract

Fucosylation of Epidermal Growth Factor-like (EGF) repeats by protein O-fucosyltransferase 1 (POFUT1 in vertebrates, OFUT1 in Drosophila) is pivotal for NOTCH function. In Drosophila OFUT1 also acts as chaperone for Notch independent from its enzymatic activity. NOTCH ligands are also substrates for POFUT1, but in Drosophila OFUT1 is not essential for ligand function. In vertebrates the significance of POFUT1 for ligand function and subcellular localization is unclear. Here, we analyze the importance of O-fucosylation and POFUT1 for the mouse NOTCH ligand Delta-like 1 (DLL1). We show by mass spectral glycoproteomic analyses that DLL1 is O-fucosylated at the consensus motif C²XXXX(S/T)C³ (where C² and C³ are the second and third conserved cysteines within the EGF repeats) found in EGF repeats 3, 4, 7 and 8. A putative site with only three amino acids between the second cysteine and the hydroxy amino acid within EGF repeat 2 is not modified. DLL1 proteins with mutated O-fucosylation sites reach the cell surface and accumulate intracellularly. Likewise, in presomitic mesoderm cells of POFUT1 deficient embryos DLL1 is present on the cell surface, and in mouse embryonic fibroblasts lacking POFUT1 the same relative amount of overexpressed wild type DLL1 reaches the cell surface as in wild type embryonic fibroblasts. DLL1 expressed in POFUT1 mutant cells can activate NOTCH, indicating that POFUT1 is not required for DLL1 function as a Notch ligand.

Subjects

Subjects :
Medicine
Science

Details

Language :
English
ISSN :
19326203
Volume :
9
Issue :
2
Database :
Directory of Open Access Journals
Journal :
PLoS ONE
Publication Type :
Academic Journal
Accession number :
edsdoj.b37817be512a4b6c8a33a7728d4e7036
Document Type :
article
Full Text :
https://doi.org/10.1371/journal.pone.0088571