| Project/Area Number |
03044095
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Institute for Protein Research, Osaka University |
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Principal Investigator |
SAKIYAMA Fumio Institute for Protein Research, Osaka University, たんぱく質研究所, 教授 (40029947)
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| Co-Investigator(Kenkyū-buntansha) |
マリリン A アンダーソ メルボルン大学植物学部, 研究員
リチャード J シンプソ ルートビヒ癌研究所, 主任研究員
エイドリアン E クラー メルボルン大学植物学部, 教授
KAWATA Yasushi Department of Engineering, Tottori University, 助教授 (40177697)
NAKANISHI Tetsu Department of Agriculture, Kobe University, 助教授 (80031227)
IRIE Masachika Hoshi College of Pharmacy, 教授 (70061265)
NORIOKA Shigemi Institute for Protein Research, Osaka University, 助手 (70198638)
TUNASAWA Susumu Institute for Protein Research, Osaka University, 助教授 (30029962)
ANDERSON Marilyn A. School of Botany, The University of Melbourne
SIMPSON Richard J. Ludwig Institute for Cancer Research
CLARKE Adrienne E. School of Botany, The University of Melbourne
クラーク エイドリアン メルボルン大学, 植物学部, 教授
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1992: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1991: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Gemetophytic self-incompatibilty / Ribonuclease / Japanese pear / Purification of stylar ribonuclease / Tobacco stylar fibonuclease / Self-compatible Japanese pear / Sー糖たんぱく質 / Sーリボヌクレア-ゼ / 自家不和合性タバコ |
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| Research Abstract |
Stylar RNases which are thought to be associated with self-incompatibility in a tobacco plant, Nicotiana alata, and Japanese pear, Pyrus serotina, were studied to gain a clue to elucidate the molecular mechanism of gametophytic selfincompatibility. For N. alata RNases, we obtained the following results. i) S-RNase was inactivated by the action of iodoacetic acid as well as Rnase T_2. Two histidine residues were mainly modified, indicating that these residues are responsible for the function of S-RNase. Location of the modified histidine residues is being studied. ii) There may be no direct relation between the substrate specificity of an S-RNase and its S-genotype as far as tested with several small substrates. iii) The gene of a stylar RNase was cloned in addition to those of two S-RNases and its nucleotide sequence was determined. Since a novel RNase different from the known S-RNases was also separated by Mono S chromatography, the enzyme was purified and its sequence analysis is now
… More
under progress. Structure information obtained by this analysis will serve to examine whether these two sequences, determined and deduced, are the same or not. A method for the micropreparation of protein was devised to analyze RNases from a single style of tobacco flower. Using this method, the appearance of the novel RNase during flower development was studied.
The presence of RNase activity in the style of self-incompatible Japanese pear was tested by the method used for N. alata. The activity was detected in all spceies tested, suggesting that stylar RNases exist for self-incompatible Japanese pear in the Rosaceae family as well as N. alata in the Solanaceae family. Furthermore, the extract of styles of a self-compatible species of Japanese pear gave positive RNase test. Since polyphenoloxidase activity was much higher in the style of Japanese pear flower than in that of N. alata flower, the conventional method for extracting RNase activity was modified to suppress the oxidase activity. Extraction efficiency was significantly increased with this modified method and RNase activity was again tested with both self-incompatible and self-compatible species. The results were consistent with those obtained previously. Individual RNases were purified by a series of chromatography after ammonium sulfate fractionation from the crude extract of styles of Japanese pear. The amino acid sequence of purified RNase is being elucidated. The RNase gene was also cloned using mRNA in the style of flowers at the bud stage and the analysis of its nucleotide sequence is in progress. The comparison of amino acid sequences of RNases between a self-incompatible species and its self-compatible mutant must provide a clue to explore the functional role of stylar RNase in the mechanism of gametophytic self-incompatibility. Less
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