title: Glycosylation modulates TRAIL-R1/death receptor 4 protein: different regulations of two pro-apoptotic receptors for TRAIL by tunicamycin.
abstract: Death receptor 4 (DR4) is a receptor of the antitumor death ligand, TNF-related apoptosis-inducing ligand (TRAIL), and is considered a promising molecular target for cancer therapy. Here, we show a novel regulation of DR4 protein. Tunicamycin treatment, which is an inducer of endoplasmic reticulum (ER)-stress, generated a lower molecular-weight pattern of DR4, but not DR5 protein in prostate cancer DU145 and PC3 cells. Thus, we termed the small form of DR4 protein, DR4-Small (DR4-S) and the large form, DR4-Large (DR4-L). Using DR4 siRNA, we confirmed that DR4-S also stands for DR4 protein. Other ER-stress inducers, brefeldin A and thapsigargin did not generate DR4-S. On the other hand, these ER-stress inducers increased DR5 protein. Tunicamycin induces ER-stress following the inhibition of N-linked glycosylation. Thus, we examined DR4 protein in cell lysates treated with glycosydase. Glycosydase treatments generated DR4-S protein, similar to tunicamycin. These results indicate that tunicamycin regulates DR4 protein size via inhibition of glycosylation.
authors.affiliation: Department of Molecular-Targeting Cancer Prevention, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan.
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Yoshida
authors.forename: Takumi
authors.initials: T
authors.lastname: Shiraishi
authors.forename: Mano
authors.initials: M
authors.lastname: Horinaka
authors.forename: Miki
authors.initials: M
authors.lastname: Wakada
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sakai
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D020126:Brefeldin A / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006031:Glycosylation; D006801:Humans; D008297:Male; D034741:RNA, Small Interfering / Q000494:pharmacology; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism*; D018124:Receptors, Tumor Necrosis Factor / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D019284:Thapsigargin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014415:Tunicamycin / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D034741:RNA, Small Interfering; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; C105190:TNFRSF10A protein, human; D014415:Tunicamycin; D020126:Brefeldin A; D019284:Thapsigargin