title: Maize opaque10 Encodes a Cereal-Specific Protein That Is Essential for the Proper Distribution of Zeins in Endosperm Protein Bodies.
abstract: Cereal storage proteins are major nitrogen sources for humans and livestock. Prolamins are the most abundant storage protein in most cereals. They are deposited into protein bodies (PBs) in seed endosperm. The inner structure and the storage mechanism for prolamin PBs is poorly understood. Maize opaque10 (o10) is a classic opaque endosperm mutant with misshapen PBs. Through positional cloning, we found that O10 encodes a novel cereal-specific PB protein. Its middle domain contains a seven-repeat sequence that is responsible for its dimerization. Its C terminus contains a transmembrane motif that is required for its ER localization and PB deposition. A cellular fractionation assay indicated that O10 is initially synthesized in the cytoplasm and then anchored to the ER and eventually deposited in the PB. O10 can interact with 19-kD and 22-kD α-zeins and 16-kD and 50-kD γ-zeins through its N-terminal domain. An immunolocalization assay indicated that O10 co-localizes with 16-kD γ-zein and 22-kD α-zein in PBs, forming a ring-shaped structure at the interface between the α-zein-rich core and the γ-zein-rich peripheral region. The loss of O10 function disrupts this ring-shaped distribution of 22-kD and 16-kD zeins, resulting in misshapen PBs. These results showed that O10, as a newly evolved PB protein, is essential for the ring-shaped distribution of 22-kD and 16-kD zeins and controls PB morphology in maize endosperm.
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Yao
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.|Coordinated Crop Biology Research Center (CBRC), Beijing, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Qi
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Yang
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.
authors.forename: Shumei
authors.initials: S
authors.lastname: Yan
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.
authors.forename: Huiling
authors.initials: H
authors.lastname: Ling
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.|Coordinated Crop Biology Research Center (CBRC), Beijing, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.|Coordinated Crop Biology Research Center (CBRC), Beijing, China.
authors.forename: Guifeng
authors.initials: G
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, Shanghai, China.|Coordinated Crop Biology Research Center (CBRC), Beijing, China.|National Maize Improvement Center of China, China Agricultural University, Beijing, China.
authors.forename: Rentao
authors.initials: R
authors.lastname: Song
mesh_terms: D002523:Edible Grain / Q000235:genetics / Q000254:growth & development; D056625:Endosperm / Q000235:genetics* / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development; D015028:Zein / Q000235:genetics / Q000378:metabolism*
chemical_list: D010940:Plant Proteins; C108912:endosperm specific protein, Zea mays; D015028:Zein