title: WFS1 protein modulates the free Ca(2+) concentration in the endoplasmic reticulum.
abstract: The WFS1 gene, encoding an endoplasmic reticulum (ER) membrane glycoprotein, is mutated in Wolfram syndrome characterized by diabetes mellitus and optic atrophy. Herein, Ca(2+) dynamics were examined in WFS1-knockdown and -overexpressing HEK293 cells. Studies using ER-targeted Ca(2+)-sensitive photoprotein aequorin demonstrated WFS1 protein to positively modulate ER Ca(2+) levels by increasing the rate of Ca(2+) uptake. Furthermore, Ca(2+) imaging with Fura-2 showed the magnitude of the store-operated Ca(2+) entry to parallel WFS1 expression levels. These data indicate that WFS1 protein participates in the regulation of cellular Ca(2+) homeostasis, at least partly, by modulating the filling state of the ER Ca(2+) store.
authors.affiliation: Division of Molecular Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Takei
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Ishihara
authors.forename: Suguru
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamada
authors.forename: Akira
authors.initials: A
authors.lastname: Tamura
authors.forename: Hideki
authors.initials: H
authors.lastname: Katagiri
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Maruyama
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Oka
mesh_terms: D001483:Base Sequence; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D034622:RNA Interference
chemical_list: D008565:Membrane Proteins; C114987:wolframin protein; D002118:Calcium