title: C-mannosylation of R-spondin3 regulates its secretion and activity of Wnt/β-catenin signaling in cells.
abstract: R-spondin3 (Rspo3) is a secreted protein, which acts as an agonist of canonical Wnt/β-catenin signaling that plays an important role in embryonic development and homeostasis. In this study, we focused on C-mannosylation, a unique type of glycosylation, of human Rspo3. Rspo3 has two putative C-mannosylation sites at Trp(153) and Trp(156) ; however, it had been unclear whether these sites are C-mannosylated or not. We demonstrated that Rspo3 was C-mannosylated at both Trp(153) and Trp(156) by mass spectrometry. Using C-mannosylation-defective Rspo3 mutant-overexpressing cell lines, we found that C-mannosylation of Rspo3 promotes its secretion and activates Wnt/β-catenin signaling.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Fujiwara
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Kato
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Niwa
authors.affiliation: Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Miyu
authors.initials: M
authors.lastname: Tsuchiya
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sasazawa
authors.affiliation: Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan.
authors.forename: Naoshi
authors.initials: N
authors.lastname: Dohmae
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan.
authors.forename: Siro
authors.initials: S
authors.lastname: Simizu
mesh_terms: D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D006031:Glycosylation; D006706:Homeostasis / Q000235:genetics; D006801:Humans; D008358:Mannose / Q000378:metabolism; D050505:Mutant Proteins / Q000096:biosynthesis* / Q000235:genetics; D019699:Thrombospondins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway / Q000235:genetics*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism; D000098907:R-Spondins
chemical_list: D008358:Mannose; D050505:Mutant Proteins; D019699:Thrombospondins; D051176:beta Catenin; C475438:RSPO3 protein, human; D000098907:R-Spondins
keywords: C-mannosylation; R-spondin3; Wnt/β-catenin signaling; glycobiology; mass spectrometry; signal transduction