scholarly journals Protein reservoirs of seeds are composites of amyloid and amyloid-like structures

2021 ◽  
Author(s):  
Nabodita Sinha ◽  
Avinash Y. Gahane ◽  
Talat Zahra ◽  
Ashwani K. Thakur
Keyword(s):  
Congo Red ◽  
Storage Proteins ◽  
Molecular Level ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Bodies ◽  
Molecular Rotor ◽  
Protein Storage ◽  
Enhanced Sensitivity ◽  
Amyloid Structures

AbstractSeed storage proteins, well-known for their nutritional functions are sequestered in protein bodies. However, their biophysical properties at the molecular level remain elusive. Based on the structure and function of protein bodies found in other organisms, we hypothesize that the seed protein bodies might be present as amyloid structures. When visualized with a molecular rotor Thioflavin-T and a recently discovered Proteostat® probe with enhanced sensitivity, the seed sections showed amyloid-like signatures in the protein storage bodies of the aleurone cells of monocots and cotyledon cells of dicots. To make the study compliant for amyloid detection, gold-standard Congo red dye was used. Positive apple-green birefringence due to Congo red affinity in some of the areas of ThT and Proteostat® binding, suggests the presence of both amyloid-like and amyloid deposits in the protein storage bodies. Further, diminishing amyloid signature in germinating seeds implies the degradation of these amyloid structures and their utilization. This study will open new research avenues for a detailed molecular-level understanding of the formation and utilization of aggregated protein bodies as well as their evolutionary roles.

scholarly journals Amino Acid Sequencing and cDNA Cloning of Rice Seed Storage Proteins, the 13kDa Prolamins, Extracted from Type I Protein Bodies.

1999 ◽  
Vol 16 (2) ◽  
pp. 103-113 ◽  
Author(s):  
Norihiro MITSUKAWA ◽  
Ryoichi KONISHI ◽  
Kunitomo KIDZU ◽  
Kozo OHTSUKI ◽  
Takehiro MASUMURA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cdna Cloning ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Bodies ◽  
Type I ◽  
Rice Seed ◽  
Amino Acid Sequencing

scholarly journals Discerning amyloid network in plants

2021 ◽  
Author(s):  
Avinash Y.Gahane ◽  
Nabodita Sinha ◽  
Talat Zahra ◽  
Ashwani K.Thakur
Keyword(s):  
Congo Red ◽  
Storage Proteins ◽  
Compositional Analysis ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Amyloid Formation ◽  
Functional Roles ◽  
Plant Seeds ◽  
Glutamine Repeat ◽  
Protein Rich

AbstractAmyloids are proteinaceous fibrillar structures and are known for their pathogenic and functional roles across the kingdoms. Besides proteinaceous deposits, amyloid-like structures are present in small metabolite assemblies and fibrillar hydrogels. Recent cryoelectron microscopy studies have shed light on the heterogeneous nature of the amyloid structures and their association with carbohydrate or lipid molecules, suggesting that amyloids are not exclusively proteinaceous. The association of amyloids with carbohydrates is further supported because the gold-standard dye of amyloid detection, Congo red, also binds to carbohydrates, probably due to similar stacking interactions. We name the association between amyloids, carbohydrates and other biomolecules as amyloid-network and propose that plants might contain such structures. Specifically, we hypothesize that cereal seeds containing glutamine-repeat-rich granules of storage proteins may have amyloid-like structures. This is because, polyQ repeats are associated with protein aggregation and amyloid formation in humans and are linked to multiple neurodegenerative conditions. Also seed storage proteins and seed cell wall proteins possess carbohydrate affinity. Thus, plant seeds might contain an intercalated network of proteins and carbohydrates, lending strength, stability and dynamics to these structures. In this paper, we show that, plant seeds have a mesh-like network that shows apple-green birefringence on staining with Congo red, a characteristic of amyloids. This congophilic network is more prominent in protein-rich seed sections of wheat and lentils, as compared to starch-rich compartments of potato. The findings suggest an amyloid network in the seeds and might be extended to other plant tissues. Further investigation with mass spectrometry and other techniques would detail the exact compositional analysis of these networks.

Trafficking to the seed protein storage vacuole

2018 ◽  
Vol 45 (9) ◽  
pp. 895
Author(s):  
Joanne R. Ashnest ◽  
Anthony R. Gendall
Keyword(s):  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Storage ◽  
Protein Storage Vacuole ◽  
2S Albumins ◽  
Vacuolar Sorting ◽  
Mechanistic Understanding ◽  
Lytic Vacuole ◽  
Storage Vacuole

The processing and subcellular trafficking of seed storage proteins is a critical area of physiological, agricultural and biotechnological research. Trafficking to the lytic vacuole has been extensively discussed in recent years, without substantial distinction from trafficking to the protein storage vacuole (PSV). However, despite some overlap between these pathways, there are several examples of unique processing and machinery in the PSV pathway. Moreover, substantial new data has recently come to light regarding the important players in this pathway, in particular, the intracellular NHX proteins and their role in regulating lumenal pH. In some cases, these new data are limited to genetic evidence, with little mechanistic understanding. As such, the implications of these data in the current paradigm of PSV trafficking is perhaps yet unclear. Although it has generally been assumed that the major classes of storage proteins are trafficked via the same pathway, there is mounting evidence that the 12S globulins and 2S albumins may be trafficked independently. Advances in identification of vacuolar targeting signals, as well as an improved mechanistic understanding of various vacuolar sorting receptors, may reveal the differences in these trafficking pathways.

Involvement of the Golgi apparatus in crystalloid protein deposition in Ricinus communis cv. Hale seeds

1990 ◽  
Vol 68 (11) ◽  
pp. 2353-2360 ◽  
Author(s):  
M. J. Brown ◽  
J. S. Greenwood
Keyword(s):  
Storage Protein ◽  
Castor Bean ◽  
Protein Transport ◽  
Storage Proteins ◽  
Ricinus Communis ◽  
Protein Body ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Bodies ◽  
11S Globulin

The developing endosperm of castor bean has been used extensively as a model system for studies of storage-protein synthesis and processing, yet the path of transport of the storage proteins to the protein bodies has not been elucidated. In this study, immunolocalization of the 11S globulin (crystalloid protein) was performed on sections of acrolein–glutaraldehydefixed, resin-embedded, developing castor bean endosperm. Acrolein allowed rapid fixation of the tissue necessary for preserving the ultrastructure of the endomembrane system while maintaining adequate antigenicity of the target protein. Crystalloid protein was localized in the rough endoplasmic reticulum, the known site of synthesis, and in the dense proteinaceous inclusions within the protein bodies. In addition, significant labelling of Golgi complexes and associated vesicles, 65-nm diameter coated vesicles, and larger 220-nm diameter cytoplasmic vesicles was obtained. The findings provide the first direct evidence that the storage parenchyma cells of developing castor bean endosperm possess well-developed, functional Golgi complexes. This is consistent with previous observations of seed storage proteins in other plant species. The study further suggests that two distinct classes of vesicles are involved in the transport of the 11S globulin to the protein bodies. Key words: Golgi, immunolocalization, protein body, Ricinus communis, storage protein, transport (protein).

scholarly journals Wheat (Triticum aestivum L.) TaHMW1D Transcript Variants Are Highly Expressed in Response to Heat Stress and in Grains Located in Distal Part of the Spike

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Two Dimensional Gel Electrophoresis ◽  
Transcript Variants

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.

scholarly journals A Single Seed Protein Extraction Protocol for Characterizing Brassica Seed Storage Proteins

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 107
Author(s):  
Mahmudur Rahman ◽  
Lei Liu ◽  
Bronwyn J. Barkla
Keyword(s):  
Seed Protein ◽  
Storage Proteins ◽  
Protein Extraction ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Yield ◽  
Tissue Type ◽  
Single Seed ◽  
Material Optimization ◽  
Hazardous Chemical

Rapeseed oil-extracted expeller cake mostly contains protein. Various approaches have been used to isolate, detect and measure proteins in rapeseeds, with a particular focus on seed storage proteins (SSPs). To maximize the protein yield and minimize hazardous chemical use, isolation costs and the loss of seed material, optimization of the extraction method is pivotal. For some studies, it is also necessary to minimize or avoid seed-to-seed cross-contamination for phenotyping and single-tissue type analysis to know the exact amount of any bioactive component in a single seed, rather than a mixture of multiple seeds. However, a simple and robust method for single rapeseed seed protein extraction (SRPE) is unavailable. To establish a strategy for optimizing SRPE for downstream gel-based protein analysis, yielding the highest amount of SSPs in the most economical and rapid way, a variety of different approaches were tested, including variations to the seed pulverization steps, changes to the compositions of solvents and reagents and adjustments to the protein recovery steps. Following SRPE, 1D-SDS-PAGE was used to assess the quality and amount of proteins extracted. A standardized SRPE procedure was developed and then tested for yield and reproducibility. The highest protein yield and quality were obtained using a ball grinder with stainless steel beads in Safe-Lock microcentrifuge tubes with methanol as the solvent, providing a highly efficient, economic and effective method. The usefulness of this SRPE was validated by applying the procedure to extract protein from different Brassica oilseeds and for screening an ethyl methane sulfonate (EMS) mutant population of Brassica rapa R-0-18. The outcomes provide useful methodology for identifying and characterizing the SSPs in the SRPE.

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