TY - JOUR
T1 - Galactose differentially modulates lunatic and manic fringe effects on Delta1-induced NOTCH signaling
AU - Hou, Xinghua
AU - Tashima, Yuko
AU - Stanley, Pamela
PY - 2012/1/2
Y1 - 2012/1/2
N2 - NOTCH signaling induced by Delta1 (DLL1) and Jagged1 (JAG1) NOTCH ligands is modulated by the β3N-acetylglucosaminyl transferase Fringe. LFNG (Lunatic Fringe) and MFNG (Manic Fringe) transferN-acetylglucosamine (GlcNAc) to O-fucose attached to EGF-like repeats of NOTCH receptors. In coculture NOTCH signaling assays, LFNG generally enhances DLL1-induced, but inhibits JAG1-induced, NOTCH signaling. In mutant Chinese hamster ovary (CHO) cells that do not add galactose (Gal) to the GlcNAc transferred by Fringe, JAG1-induced NOTCH signaling is not inhibited by LFNG or MFNG. In mouse embryos lacking B4galt1, NOTCH signaling is subtly reduced during somitogenesis. Here we show that DLL1-induced NOTCH signaling in CHO cells was enhanced by LFNG, but this did not occur in either Lec8 or Lec20 CHO mutants lacking Gal on O-fucose glycans. Lec20 mutants corrected with a B4galt1 cDNA became responsive to LFNG. By contrast, MFNG promoted DLL1-induced NOTCH signaling better in the absence of Gal than in its presence. This effect was reversed in Lec8 cells corrected by expression of a UDP-Gal transporter cDNA. The MFNG effect was abolished by a DDD to DDA mutation that inactivates MFNG GlcNAc transferase activity. The binding of soluble NOTCH ligands and NOTCH1/EGF1-36 generally reflected changes in NOTCH signaling caused by LFNG and MFNG. Therefore, the presence of Gal on O-fucose glycans differentially affects DLL1-induced NOTCH signaling modulated by LFNG versus MFNG. Gal enhances the effect of LFNG but inhibits the effect of MFNG on DLL1-induced NOTCH signaling, with functional consequences for regulating the strength of NOTCH signaling.
AB - NOTCH signaling induced by Delta1 (DLL1) and Jagged1 (JAG1) NOTCH ligands is modulated by the β3N-acetylglucosaminyl transferase Fringe. LFNG (Lunatic Fringe) and MFNG (Manic Fringe) transferN-acetylglucosamine (GlcNAc) to O-fucose attached to EGF-like repeats of NOTCH receptors. In coculture NOTCH signaling assays, LFNG generally enhances DLL1-induced, but inhibits JAG1-induced, NOTCH signaling. In mutant Chinese hamster ovary (CHO) cells that do not add galactose (Gal) to the GlcNAc transferred by Fringe, JAG1-induced NOTCH signaling is not inhibited by LFNG or MFNG. In mouse embryos lacking B4galt1, NOTCH signaling is subtly reduced during somitogenesis. Here we show that DLL1-induced NOTCH signaling in CHO cells was enhanced by LFNG, but this did not occur in either Lec8 or Lec20 CHO mutants lacking Gal on O-fucose glycans. Lec20 mutants corrected with a B4galt1 cDNA became responsive to LFNG. By contrast, MFNG promoted DLL1-induced NOTCH signaling better in the absence of Gal than in its presence. This effect was reversed in Lec8 cells corrected by expression of a UDP-Gal transporter cDNA. The MFNG effect was abolished by a DDD to DDA mutation that inactivates MFNG GlcNAc transferase activity. The binding of soluble NOTCH ligands and NOTCH1/EGF1-36 generally reflected changes in NOTCH signaling caused by LFNG and MFNG. Therefore, the presence of Gal on O-fucose glycans differentially affects DLL1-induced NOTCH signaling modulated by LFNG versus MFNG. Gal enhances the effect of LFNG but inhibits the effect of MFNG on DLL1-induced NOTCH signaling, with functional consequences for regulating the strength of NOTCH signaling.
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U2 - 10.1074/jbc.M111.317578
DO - 10.1074/jbc.M111.317578
M3 - Article
C2 - 22081605
AN - SCOPUS:84855290478
SN - 0021-9258
VL - 287
SP - 474
EP - 483
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -