title: Protein disulfide isomerase-like protein 1-1 controls endosperm development through regulation of the amount and composition of seed proteins in rice.
abstract: Protein disulfide isomerase (PDI) is a chaperone protein involved in oxidative protein folding by acting as a catalyst and assisting folding in the endoplasmic reticulum (ER). A genome database search showed that rice contains 19 PDI-like genes. However, their functions are not clearly identified. This paper shows possible functions of rice PDI-like protein 1-1 (PDIL1-1) during seed development. Seeds of the T-DNA insertion PDIL1-1 mutant, PDIL1-1Δ, identified by genomic DNA PCR and western blot analysis, display a chalky phenotype and a thick aleurone layer. Protein content per seed was significantly lower and free sugar content higher in PDIL1-1Δ mutant seeds than in the wild type. Proteomic analysis of PDIL1-1Δ mutant seeds showed that PDIL1-1 is post-translationally regulated, and its loss causes accumulation of many types of seed proteins including glucose/starch metabolism- and ROS (reactive oxygen species) scavenging-related proteins. In addition, PDIL1-1 strongly interacts with the cysteine protease OsCP1. Our data indicate that the opaque phenotype of PDIL1-1Δ mutant seeds results from production of irregular starch granules and protein body through loss of regulatory activity for various proteins involved in the synthesis of seed components.
authors.affiliation: Department of Plant Science, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Korea.
authors.forename: Yeon Jeong
authors.initials: YJ
authors.lastname: Kim
authors.forename: Song Yion
authors.initials: SY
authors.lastname: Yeu
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Park
authors.forename: Hee-Jong
authors.initials: HJ
authors.lastname: Koh
authors.forename: Jong Tae
authors.initials: JT
authors.lastname: Song
authors.forename: Hak Soo
authors.initials: HS
authors.lastname: Seo
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D018744:DNA, Plant / Q000235:genetics; D015180:Electrophoresis, Gel, Two-Dimensional; D056625:Endosperm / Q000254:growth & development*; D055786:Gene Knockout Techniques; D009154:Mutation; D012275:Oryza / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D019704:Protein Disulfide-Isomerases / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012639:Seeds / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D017931:DNA Primers; D018744:DNA, Plant; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D019704:Protein Disulfide-Isomerases