The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Kerry C. Huber - One of the best experts on this subject based on the ideXlab platform.
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physicochemical properties and amylopectin fine structures of a and b type Granules of waxy and normal soft wheat starch
Journal of Cereal Science, 2010Co-Authors: Hyunseok Kim, Kerry C. HuberAbstract:This work fractionated waxy and normal wheat starches into highly purified A- and B-type Granule fractions, which were representative of native Granule populations within parent native wheat starches, to accurately assess starch characteristics and properties of the two Granule types. Wheat starch A- and B-type Granules possessed different morphologies, Granule specific surface area measurements, compositions, relative crystallinities, amylopectin branch chain distributions, and physical properties (swelling, gelatinization, and pasting behaviors). Within a genotype, total and apparent amylose contents were greater for A-type Granules, while lipid-complexed amylose and phospholipid contents were greater for B-type Granules. B-type (relative to A-type) Granules within a given genotype possessed a greater abundance of short amylopectin branch chains (DPn 33) branch chains, contributing to their lower relative crystallinities. Variation in amylose and phospholipid characteristics appeared to account for observed differences in swelling, gelatinization, and pasting properties between waxy and normal wheat starch fractions of a common Granule type. However, starch Granule swelling and gelatinization property differences between A- and B-type Granules within a given genotype were most consistently explained by their differential amylopectin chain-length distributions.
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Channels within soft wheat starch A- and B-type Granules
Journal of Cereal Science, 2008Co-Authors: Kerry C. HuberAbstract:The nature of channels within wheat starch Granules was investigated using scanning electron and confocal laser scanning microscopy. A-type Granules stained with 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA, protein-specific probe) revealed a network of radially oriented, channel-like protein structures similar to those previously reported. However, treatment of the same starch Granules with methanolic merbromin (fluorescent dye) solution, which is used to highlight external Granule surfaces (including those of channels) under non-swelling conditions, revealed few, if any, channels extending into the Granule interior. This discrepancy suggested that channels within wheat starch Granules were filled at least in part with protein. Removal of protein with protease facilitated greater access of methanolic merbromin to channels and/or cavities for both Granule types. For A-type starch Granules, relatively large channels were observed in the equatorial groove region, while finer channels originated from other regions of the Granule. This work reports the first visualization of B-type Granule channels, which most frequently occurred as less-defined voids (as opposed to the fine, discrete channels of A-type Granules) extending to Granule surfaces. Channels of A- and B-type starch Granules appeared to facilitate transfer of chemical reagent into the Granule matrix, though this effect was aided by Granule swelling (hydration) and/or removal of channel-associated protein.
Sadie Miki Sakurada - One of the best experts on this subject based on the ideXlab platform.
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ulk1 and ulk2 regulate stress Granule disassembly through phosphorylation and activation of vcp p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
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ULK1 and ULK2 Regulate Stress Granule Disassembly Through Phosphorylation and Activation of VCP/p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
Kay Trafford - One of the best experts on this subject based on the ideXlab platform.
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starch Granule morphology in oat endosperm
Journal of Cereal Science, 2017Co-Authors: Benedetta Saccomanno, Alan H Chambers, Alec Hayes, Ian Mackay, Simon C Mcwilliam, Kay TraffordAbstract:Mature and developing oat (Avena sativa) grains were sectioned and image analysis methods used to estimate the starch Granule-size distribution and morphology in endosperm cells. This showed that oat endosperm cells contain two types of starch Granule: compound starch Granules such as those seen in rice endosperm and in most other grasses; and simple Granules similar to the B-type starch Granules seen in the endosperm of Triticeae species such as wheat (Triticum aestivum). The simple Granules in oats are similar in size and relative abundance to B-type Granules in Triticeae suggesting that they may share a common evolutionary origin. However, there is a fundamental difference between oats and Triticeae in the timing of Granule initiation during grain development. In Triticeae, the B-type Granules initiate several days after the A-type Granules whereas in oats, both the simple and compound Granule types initiate at the same time, in early grain development.
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identification of a major qtl controlling the content of b type starch Granules in aegilops
Journal of Experimental Botany, 2011Co-Authors: Thomas P Howard, Nur Ardiyana Rejab, Simon Griffiths, Fiona J Leigh, Michelle Leveringtonwaite, James Simmonds, Cristobal Uauy, Kay TraffordAbstract:Starch within the endosperm of most species of the Triticeae has a unique bimodal Granule morphology comprising large lenticular A-type Granules and smaller near-spherical B-type Granules. However, a few wild wheat species (Aegilops) are known to lack B-Granules. Ae. peregrina and a synthetic tetraploid Aegilops with the same genome composition (SU) were found to differ in B-Granule number. The synthetic tetraploid had normal A- and B-type starch Granules whilst Ae. peregrina had only A-Granules because the B-Granules failed to initiate. A population segregating for B-Granule number was generated by crossing these two accessions and was used to study the genetic basis of B-Granule initiation. A combination of Bulked Segregant Analysis and QTL mapping identified a major QTL located on the short arm of chromosome 4S that accounted for 44.4% of the phenotypic variation. The lack of B-Granules in polyploid Aegilops with diverse genomes suggests that the B-Granule locus has been lost several times independently during the evolution of the Triticeae. It is proposed that the B-Granule locus is susceptible to silencing during polyploidization and a model is presented to explain the observed data based on the assumption that the initiation of B-Granules is controlled by a single major locus per haploid genome.
James Messing - One of the best experts on this subject based on the ideXlab platform.
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ulk1 and ulk2 regulate stress Granule disassembly through phosphorylation and activation of vcp p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
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ULK1 and ULK2 Regulate Stress Granule Disassembly Through Phosphorylation and Activation of VCP/p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
Bo Wang - One of the best experts on this subject based on the ideXlab platform.
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ulk1 and ulk2 regulate stress Granule disassembly through phosphorylation and activation of vcp p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
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ULK1 and ULK2 Regulate Stress Granule Disassembly Through Phosphorylation and Activation of VCP/p97
Molecular Cell, 2019Co-Authors: Bo Wang, Timothy I. Shaw, Brian A Maxwell, Youngdae Gwon, James Messing, Amber L Ward, Honghu Quan, Ashutosh Mishra, Sadie Miki SakuradaAbstract:Summary Disturbances in autophagy and stress Granule dynamics have been implicated as potential mechanisms underlying inclusion body myopathy (IBM) and related disorders. Yet the roles of core autophagy proteins in IBM and stress Granule dynamics remain poorly characterized. Here, we demonstrate that disrupted expression of the core autophagy proteins ULK1 and ULK2 in mice causes a vacuolar myopathy with ubiquitin and TDP-43–positive inclusions; this myopathy is similar to that caused by VCP/p97 mutations, the most common cause of familial IBM. Mechanistically, we show that ULK1/2 localize to stress Granules and phosphorylate VCP, thereby increasing VCP’s activity and ability to disassemble stress Granules. These data suggest that VCP dysregulation and defective stress Granule disassembly contribute to IBM-like disease in Ulk1/2-deficient mice. In addition, stress Granule disassembly is accelerated by an ULK1/2 agonist, suggesting ULK1/2 as targets for exploiting the higher-order regulation of stress Granules for therapeutic intervention of IBM and related disorders.
