An Aspartic Endopeptidase is Involved in the Breakdown of Propeptides of Storage Proteins in Protein-Storage Vacuoles of Plants
| العنوان: | An Aspartic Endopeptidase is Involved in the Breakdown of Propeptides of Storage Proteins in Protein-Storage Vacuoles of Plants |
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| المؤلفون: | Nagako Hiraiwa, Mikio Nishimura, Maki Kondo, Ikuko Hara-Nishimura |
| المصدر: | European Journal of Biochemistry. 246:133-141 |
| بيانات النشر: | Wiley, 1997. |
| سنة النشر: | 1997 |
| مصطلحات موضوعية: | DNA, Complementary, endocrine system diseases, Immunoblotting, Molecular Sequence Data, Protein storage vacuole, Ricin, Vacuole, Biology, Biochemistry, Endosperm, Aspartic Acid Endopeptidases, Storage protein, Amino Acid Sequence, Protein Precursors, Microscopy, Immunoelectron, Protein precursor, Plant Proteins, chemistry.chemical_classification, Endoplasmic reticulum, Seed Storage Proteins, Albumin, Electrophoresis, Capillary, food and beverages, Antigens, Plant, Hydrogen-Ion Concentration, Castor Bean, Plants, Toxic, chemistry, Seeds, Vacuoles, Electrophoresis, Polyacrylamide Gel, Plant Lectins, Cell fractionation, Peptides, Protein Processing, Post-Translational, Sequence Alignment, 2S Albumins, Plant |
| الوصف: | To understand the mechanism of the maturation of various proteins in protein-storage vacuoles, we purified a 48-kDa aspartic endopeptidase composed of 32-kDa and 16-kDa subunits from castor bean. Immunocytochemical and cell fractionation analyses of the endosperm of maturing castor bean seed showed that the aspartic endopeptidase was localized in the matrix of the protein-storage vacuoles, where a variety of seed storage proteins were also present. The amount of the aspartic endopeptidase increased at the mid-maturation stage of the seeds before accumulation of the storage proteins. To determine how the aspartic endopeptidase is responsible for maturation of seed proteins in concert with the vacuolar processing enzyme, we prepared 35S-labeled proproteins of seed proteins from the endoplasmic reticulum fraction of pulse-labeled maturing endosperm and used the authentic proproteins as substrates for in vitro processing experiments. The purified aspartic endopeptidase was unable to convert any of three endosperm proproteins, pro2S albumin, proglobulin, and proricin, into their mature sizes, while the purified vacuolar processing enzyme could convert all three proproteins. We further examined the activity of aspartic endopeptidase on the cleavage of an internal propeptide of Arabidopsis pro2S albumin, which is known to be removed post-translationally. The aspartic endopeptidase cleaved the propeptide at three sites under acidic conditions. These results suggest that aspartic endopeptidase cannot directly convert pro2S albumin into the mature form, but it may play a role in trimming the C-terminal propeptides from the subunits that are produced by the action of the vacuolar processing enzyme. |
| تدمد: | 1432-1033 0014-2956 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ca960d2bf0962c9cfb992f9c089353f3Test https://doi.org/10.1111/j.1432-1033.1997.00133.xTest |
| حقوق: | CLOSED |
| رقم الانضمام: | edsair.doi.dedup.....ca960d2bf0962c9cfb992f9c089353f3 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14321033 00142956 |
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