title: Deposition of a recombinant peptide in ER-derived protein bodies by retention with cysteine-rich prolamins in transgenic rice seed.
abstract: A 7Crp peptide composed of seven major human T cell epitopes derived from the Japanese cedar pollen allergens Cry j 1 and Cry j 2 is an ideal tolerogen for peptide immunotherapy against Japanese cedar pollinosis. To maximize the accumulation level of the 7Crp peptide in transgenic rice seed, we tested endosperm specific promoters and intracellular localizations suitable for stable accumulation. A 7Crp peptide carrying the KDEL ER retention signal directed by the 2.3-kb promoter of the glutelin GluB-1, which contains a signal peptide, accumulated at the highest level of about 60 microg/grain. Notably, the 7Crp peptide predominantly accumulated in ER-derived protein bodies irrespective of the presence of various sorting signals or expression as a fusion protein with glutelin. We attribute this abnormal pattern of accumulation to the formation of disulfide bonds between the 7Crp peptide and cysteine-rich (Cys-rich) prolamin storage proteins. Furthermore, the formation of these aggregates induced the chaperone proteins BiP and PDI as an ER stress response.
authors.affiliation: Transgenic Crop Research and Development Center, National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan. takaiwa@nias.affrc.go.jp
authors.forename: Fumio
authors.initials: F
authors.lastname: Takaiwa
authors.forename: Sakiko
authors.initials: S
authors.lastname: Hirose
authors.forename: Hidenori
authors.initials: H
authors.lastname: Takagi
authors.forename: Lijun
authors.initials: L
authors.lastname: Yang
authors.forename: Yuhya
authors.initials: Y
authors.lastname: Wakasa
mesh_terms: D015153:Blotting, Western; D003545:Cysteine / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D042541:Intracellular Space / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D018832:Molecular Chaperones / Q000378:metabolism; D009928:Organ Specificity; D012275:Oryza / Q000166:cytology / Q000235:genetics* / Q000648:ultrastructure; D010455:Peptides / Q000378:metabolism*; D030821:Plants, Genetically Modified; D055315:Prolamins / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism*; D012639:Seeds / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D018832:Molecular Chaperones; D010455:Peptides; D055315:Prolamins; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D003545:Cysteine