The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Gad Galili - One of the best experts on this subject based on the ideXlab platform.
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Wheat storage Proteins : Assembly, transport and deposition in Protein Bodies
Plant Physiology and Biochemistry, 1996Co-Authors: Gad Galili, Yuval Shimoni, S. Giorini-silfen, Hanna Levanony, Yoram Altschuler, N. ShaniAbstract:Wheat storage Proteins are co-translationally inserted into the endoplasmic reticulum (ER) and then accumulate in Protein Bodies inside vacuoles. It appears that a significant amount of these storage Proteins assemble into Protein Bodies within the ER and that these Protein Bodies are subsequently internalized into vacuoles by a process that is analogous to autophagy and does not utilize the Golgi complex. Folding and assembly of the storage Proteins within the ER is not a spontaneous process, but is apparently assisted by ER-resident Proteins. These include molecular chaperones as well as enzymes that catalyze the formation, isomerization and perhaps also dissociation of disulfide bonds.
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Evidence for the presence of two different types of Protein Bodies in wheat endosperm.
Plant physiology, 1992Co-Authors: Regina Rubin, Hanna Levanony, Gad GaliliAbstract:Storage Proteins of wheat grains (Triticum L. em Thell) are deposited in Protein Bodies inside vacuoles. However, the subcellular sites and mechanisms of their aggregation into Protein Bodies are not clear. In the present report, we provide evidence for two different types of Protein Bodies, low- and high-density types that accumulate concurrently and independently in developing wheat endosperm cells. Gliadins were present in both types of Protein Bodies, whereas the high molecular weight glutenins were localized mainly in the dense ones. Pulse-chase experiments verified that the dense Protein Bodies were not formed by a gradual increase in density but, presumably, by a distinct, quick process of storage Protein aggregation. Subcellular fractionation and electron microscopy studies revealed that the wheat homolog of immunoglobulin heavy-chain-binding Protein, an endoplasmic reticulum-resident Protein, was present within the dense Protein Bodies, implying that these were formed by aggregation of storage Proteins within the endoplasmic reticulum. The present results suggest that a large part of wheat storage Proteins aggregate into Protein Bodies within the rough endoplasmic reticulum. Because these Protein Bodies are too large to enter the Golgi, they are likely to be transported directly to vacuoles. This route may operate in concert with the known Golgi-mediated transport to vacuoles in which the storage Proteins apparently condense into Protein Bodies at a postendoplasmic reticulum location. Our results further suggest that although gliadins are transported by either one of these routes, the high molecular weight glutenins use only the Golgi bypass route.
Brian A Larkins - One of the best experts on this subject based on the ideXlab platform.
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THE DEVELOPMENT AND IMPORTANCE OF ZEIN Protein Bodies IN MAIZE ENDOSPERM
Maydica, 2006Co-Authors: David R. Holding, Brian A LarkinsAbstract:Research over the last fifty years has shown that the vitreousness of the maize kernel is influenced by the formation of zein Protein Bodies. Here we summarize what is known about the structure and importance of Protein Bodies, beginning with their first detailed charac- terization by Donald Duvick in the 1950s. We describe the Proteins that compose zein Protein Bodies and ex- plain how available data describing zein gene expression and zein Protein interactions suggest a model for their ini- tiation, expansion and structure. We also describe maize mutants with reduced kernel hardness and show that they can be explained as a result of a perturbation to zein pro- tein structure and its effect on Protein body formation. However, there are other soft kernel mutants that appear to be unrelated to zein Proteins, indicating that much re- mains to be learned about the factors influencing the tex- ture of mature maize endosperm.
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The maize gamma-zein sequesters alpha-zein and stabilizes its accumulation in Protein Bodies of transgenic tobacco endosperm.
The Plant Cell, 1996Co-Authors: Craig E. Coleman, Koichi Takasaki, Eliot M Herman, Brian A LarkinsAbstract:Zeins are seed storage Proteins that form accretions called Protein Bodies in the rough endoplasmic reticulum of maize endosperm cells. Four types of zeins, alpha, beta, gamma, and delta, aggregate in a distinctive spatial pattern within the Protein body. We created transgenic tobacco plants expressing alpha-zein, gamma-zein, or both to examine the interactions between these Proteins leading to the formation of Protein Bodies in the endosperm. Whereas gamma-zein accumulated in seeds of these plants, stable accumulation of alpha-zein required simultaneous synthesis of gamma-zein. The zein Proteins formed accretions in the endoplasmic reticulum similar to those in maize endosperm. Protein Bodies were also found in Protein storage vacuoles. The accumulation of both types of zeins peaked early in development and declined during maturation. Even in the presence of gamma-zein, there was a turnover of alpha-zein, suggesting that the interaction between the two Proteins might be transitory. We suggest that gamma-zein plays an important role in Protein body formation and demonstrate the utility of tobacco for studying interactions between different zeins.
Cécile Mangavel - One of the best experts on this subject based on the ideXlab platform.
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Protein Bodies ontogeny and localization of prolamin components in the developing endosperm of wheat caryopses
Journal of Cereal Science, 2008Co-Authors: Céline Loussert, Yves Popineau, Cécile MangavelAbstract:Abstract During caryopsis development, prolamins are initially stored in individual Protein Bodies, then generate a Protein matrix in the ripe caryopsis. The ontogeny of the Protein Bodies was analyzed by fluorescence and electron microscopy from 7 to 43 days after anthesis (dAA), a period of time from the cellularization of endosperm to its desiccation. A series of antiBodies specific to each prolamin type ( α / β -, γ -, ω -gliadins, low-molecular weight and high-molecular weight glutenin subunits) made it possible to localize and co-localize the different prolamins in organelles of endosperm cells at different developmental stages. Protein Bodies containing prolamins were observed as early as 7 dAA. At the early developmental stages, Protein Bodies were spherical with diameters around 1–2 μm. Later, around 15 dAA, the PBs enlarged, and aggregation and/or coalescence were prominent at 21 dAA. From 33 dAA, individual PBs were no longer visible, but a Protein matrix was confined in the space between starch granules. All prolamins were found in the same Protein Bodies, without any segregation according to their types. Immunochemical labelling of prolamins failed to reveal in TEM analyses any particular internal organization in Protein Bodies. Glutenin subunits and gliadins were observed in the Golgi apparatus at the early stages of endosperm development.
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Protein Bodies ontogeny and localization of prolamin components in the developing endosperm of wheat caryopses
Journal of Cereal Science, 2008Co-Authors: Céline Loussert, Yves Popineau, Cécile MangavelAbstract:During caryopsis development, prolamins are initially stored in individual Protein Bodies, then generate a Protein matrix in the ripe caryopsis. The ontogeny of the Protein Bodies was analyzed by fluorescence and electron microscopy from 7 to 43 days after anthesis (dAA), a period of time from the cellularization of endosperm to its desiccation. A series of antiBodies specific to each prolamin type (alpha/beta-, gamma-, omega-gliadins, low-molecular weight and high-molecular weight glutenin subunits) made it possible to localize and co-localize the different prolamins in organelles of endosperm cells at different developmental stages. Protein Bodies containing prolamins were observed as early as 7 dAA. At the early developmental stages, Protein Bodies were spherical with diameters around 1-2 mu m. Later, around 15 dAA, the PBs enlarged, and aggregation and/or coalescence were prominent at 21 dAA. From 33 dAA, individual PBs were no longer visible, but a Protein matrix was confined in the space between starch granules. All prolamins were found in the same Protein Bodies, without any segregation according to their types. Immunochemical labelling of prolamins failed to reveal in TEM analyses any particular internal organization in Protein Bodies. Glutenin subunits and gliadins were observed in the Golgi apparatus at the early stages of endosperm development.
Jean Benoît Peltier - One of the best experts on this subject based on the ideXlab platform.
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Proteomic characterisation of endoplasmic reticulum-derived Protein Bodies in tobacco leaves
BMC plant biology, 2012Co-Authors: Minu Joseph, M. Dolors Ludevid, Margarita Torrent, Valerie Rofidal, Marc Tauzin, Michel Rossignol, Jean Benoît PeltierAbstract:Background The N-terminal proline-rich domain (Zera) of the maize storage Protein γ-zein, is able to induce the formation of endoplasmic reticulum (ER)-derived Protein Bodies (PBs) when fused to Proteins of interest. This encapsulation enables a recombinant fused Protein to escape from degradation and facilitates its recovery from plant biomass by gradient purification. The aim of the present work was to evaluate if induced PBs encapsulate additional Proteins jointly with the recombinant Protein. The exhaustive analysis of Protein composition of PBs is expected to facilitate a better understanding of PB formation and the optimization of recombinant Protein purification approaches from these organelles.
Baiqu Huang - One of the best experts on this subject based on the ideXlab platform.
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The Ultrastructural Evidence on the Origin of Protein Bodies in the Rough Endoplasmic Reticulum of Developing Cotyledons of Soybean
Annals of Botany, 1992Co-Authors: Yizhi Zheng, Shui Hao, Baiqu HuangAbstract:The direct development of Protein Bodies from rough endoplasmic reticulum at the late stages of soybean seed development is reported.Meanwhile, a detailed ultrastructural examination upon the cotyledon cells during Protein body formation has been made, and some structures which have not been reported before are observed and described
