title: Multivesicular body formation enhancement and exosome release during endoplasmic reticulum stress.
abstract: The endoplasmic reticulum (ER) plays a pivotal role in maintaining cellular homeostasis. However, numerous environmental and genetic factors give rise to ER stress by inducing an accumulation of unfolded proteins. Under ER stress conditions, cells initiate the unfolded protein response (UPR). Here, we demonstrate a novel aspect of the UPR by electron microscopy and immunostaining analyses, whereby multivesicular body (MVB) formation was enhanced after ER stress. This MVB formation was influenced by inhibition of ER stress transducers inositol required enzyme 1 (IRE1) and PKR-like ER kinase (PERK). Furthermore, exosome release was also increased during ER stress. However, in IRE1 or PERK deficient cells, exosome release was not upregulated, indicating that IRE1- and PERK-mediated pathways are involved in ER stress-dependent exosome release.
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan. Electronic address: soshikanemoto@hiroshima-u.ac.jp.
authors.forename: Soshi
authors.initials: S
authors.lastname: Kanemoto
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Nitani
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Murakami
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kaneko
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Asada
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Matsuhisa
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
authors.affiliation: Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553, Japan. Electronic address: imaizumi@hiroshima-u.ac.jp.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Imaizumi
mesh_terms: D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D004722:Endoribonucleases / Q000378:metabolism*; D055354:Exosomes / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D057146:Multivesicular Bodies / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction; D019892:eIF-2 Kinase / Q000378:metabolism*
chemical_list: C460640:EIF2AK3 protein, human; C528229:ERN1 protein, human; D017346:Protein Serine-Threonine Kinases; D019892:eIF-2 Kinase; D004722:Endoribonucleases
keywords: Endoplasmic reticulum; Exosome; IRE1; Multivesicular body; PERK