N-glycosylation of mouse TRAIL-R and human TRAIL-R1 enhances TRAIL-induced death

Abstract

APO2L/TRAIL (TNF-related apoptosis-inducing ligand) induces death of tumor cells through two agonist receptors, TRAIL-R1 and TRAIL-R2. We demonstrate here that N-linked glycosylation (N-glyc) plays also an important regulatory role for TRAIL-R1-mediated and mouse TRAIL receptor (mTRAIL-R)-mediated apoptosis, but not for TRAIL-R2, which is devoid of N-glycans. Cells expressing N-glyc-defective mutants of TRAIL-R1 and mouse TRAIL-R were less sensitive to TRAIL than their wild-type counterparts. Defective apoptotic signaling by N-glyc-deficient TRAIL receptors was associated with lower TRAIL receptor aggregation and reduced DISC formation, but not with reduced TRAIL-binding affinity. Our results also indicate that TRAIL receptor N-glyc impacts immune evasion strategies. The cytomegalovirus (CMV) UL141 protein, which restricts cell-surface expression of human TRAIL death receptors, binds with significant higher affinity TRAIL-R1 lacking N-glyc, suggesting that this sugar modification may have evolved as a counterstrategy to prevent receptor inhibition by UL141. Altogether our findings demonstrate that N-glyc of TRAIL-R1 promotes TRAIL signaling and restricts virus-mediated inhibition.

Death receptor 5 is activated by fucosylation in colon cancer cells

“…Here we further show that this insensitivity is not related to a lack of surface expression levels of DR5, but to a specific lack of fucosylation. This finding is in line with earlier observations that TRAIL-sensitive colon adenocarcinoma cell lines show relatively high mRNA levels of FUT3 and FUT6, while the TRAIL-resistant cell lines, such as DLD-1 and HCT 116, show low expression of FUT3 and FUT6 [24,37]. Reduction in the number of fucosyl attachment sites by pretreatment with the Oglycosylation inhibitor bGalNAc led to decreased TRAIL sensitivity via DR5 in all three cell lines mentioned, as determined by us using TRAIL-death receptor specific variants.…”

NR4A1 Promotes Diabetic Nephropathy by Activating Mff-Mediated Mitochondrial Fission and Suppressing Parkin-Mediated Mitophagy

“…Red-orange fluorescence was attributable to potential-dependent aggregation in the mitochondria. Green fluorescence, indicating the monomeric form of JC-1, appeared in the cytosol after mitochondrial membrane depolarization [48]. In the mPTP opening assay, calcein-acetoxymethyl ester (5 μM, cat.…”

Ligand nanovectorization using graphene to target cellular death receptors of cancer cell

“…For instance, it has been demonstrated that Nglycosylated DR4 was responsible for a strongest receptor response to the TRAIL attachment. 40 On the other hand, another study proves that an elevated expression of O-glycosylation of the DR5 correlates with higher sensitivity to TRAIL-mediated apoptosis in a large number of tumor cell lines. 41 Other works stipulated that both receptors are expressed simultaneously on the same cell and the binding of TRAIL necessitated only nanomolar affinity to be effective.…”

“…Although this assertion has been recently reversed, modification of DR4 or DR5 are often at the origin of the TRAIL‐sensitivity increase by promoting ligand‐induced receptor clustering and consequent caspase 8 activation. For instance, it has been demonstrated that N‐glycosylated DR4 was responsible for a strongest receptor response to the TRAIL attachment . On the other hand, another study proves that an elevated expression of O‐glycosylation of the DR5 correlates with higher sensitivity to TRAIL‐mediated apoptosis in a large number of tumor cell lines .…”

“…But for pH > 7. 40, the thermodynamic analysis demonstrated that van der Waals and hydrogen bonds governed the strong TRAIL/DR5 association due to the negative values of the enthalpy (ΔH ) and the entropy (ΔS *). 12 Here, the DR4 (5CIR structure) conformation was extracted from crystallization at pH = 5.00 while DR5 (1D0G structure) was obtained at pH = 7.50.…”