title: Fluorogenic probes reveal a role of GLUT4 N-glycosylation in intracellular trafficking.
abstract: Glucose transporter 4 (GLUT4) is an N-glycosylated protein that maintains glucose homeostasis by regulating the protein translocation. To date, it has been unclear whether the N-glycan of GLUT4 contributes to its intracellular trafficking. Here, to clarify the role of the N-glycan, we developed fluorogenic probes that label cytoplasmic and plasma-membrane proteins for multicolor imaging of GLUT4 translocation. One of the probes, which is cell impermeant, selectively detected exocytosed GLUT4. Using this probe, we verified the 'log' of the trafficking, in which N-glycan-deficient GLUT4 was transiently translocated to the cell membrane upon insulin stimulation and was rapidly internalized without retention on the cell membrane. The results strongly suggest that the N-glycan functions in the retention of GLUT4 on the cell membrane. This study showed the utility of the fluorogenic probes and indicated that this imaging tool will be applicable for research on various membrane proteins that show dynamic changes in localization.
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Hirayama
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.|Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.|JST, PRESTO, Suita, Osaka, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Hori
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Benedek
authors.affiliation: Glycometabolome Team, RIKEN Global Research Cluster, Wako, Saitama, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.|Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Kikuchi
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D005456:Fluorescent Dyes / Q000032:analysis* / Q000737:chemistry; D051275:Glucose Transporter Type 4 / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D006367:HeLa Cells; D006801:Humans; D015394:Molecular Structure; D021381:Protein Transport
chemical_list: D005456:Fluorescent Dyes; D051275:Glucose Transporter Type 4; C495692:SLC2A4 protein, human