1998 Fiscal Year Annual Research Report

低温適応と低温耐性の分子機構

Research Project

Project/Area Number	08102011
Research Institution	Okazaki National Research Institutes
Principal Investigator	村田紀夫岡崎国立共同研究機構, 基礎生物学研究所, 教授 (90011569)
Co-Investigator(Kenkyū-buntansha)	鈴木石根岡崎国立共同研究機構, 基礎生物学研究所, 助手 (10290909) 西山佳孝岡崎国立共同研究機構, 基礎生物学研究所, 助手 (30281588) 坂本敦岡崎国立共同研究機構, 基礎生物学研究所, 助手 (60270477)
Keywords	低温適応 / 低温耐性 / 不飽和化酵素 / 不飽和膜脂質 / ベタイン / 低温シグナル / 低温センサー
Research Abstract	(1) 低温と凍結に対する不飽和膜脂質の保護効果の研究: 不飽和化酵素の遺伝子破壊により膜脂質の不飽和結合数を段階的に変化させたラン藻を用いて,これまでに不飽和結合が光合成機構の安定化にとって重要なことを明らかにしてきた。今年度はその分子機構を解析し,低温に対する不飽和膜脂質の保護効果の作用部位が光化学系II複合体のD1タンパク質の新規合成とそのプロセシングにあることを明らかにした。今後は,タンパク質の合成と膜透過に対する低温と膜脂質の流動性(不飽和結合)の拮抗的効果の分子機構を明らかにしていく。 (2) 低温と凍結に対するベタインの保護効果の研究: ベタイン合成能を獲得した形質転換アラビドプシスを用いて,ベタインが低温のみならず凍結に対する耐性を増強することを明らかにした。また種子の吸水時と発芽時における低温耐性、高温耐性も増強されていることも明らかにした。これらのベタインの保護効果の分子機構として,タンパク質合成の促進ならびにタンパク質の高次構造と膜構造の安定化の作用を推定している。今後は生殖段階におけるベタインの保護効果を研究するとともに,ベタインの保護効果の分子機構を解析する予定である。 (3) 新しい低温適応因子の研究: 不飽和膜脂質とベタイン以外の低温適応因子を検索すべく,不飽和化酵素の遺伝子破壊により温度に依存した膜脂質の不飽和化機能を失ったラン藻の変異株を用いて研究を進めている。 (4) 低温センサーと低温シグナル伝達系の研究: 低温誘導性の不飽和化酵素の遺伝子のプロモーター領域にルシフェラーゼの構造遺伝子を結合したキメラ遺伝子を持つ形質転換ラン藻を作製した。これにカセットミュータジェネシスを施し,ルシフェラーゼによる低温依存性の発光に異常をきたした遺伝子破壊株を18株取得した。このうち14株については変異遺伝子を同定し,これらの中から低温センサーと低温シグナルの伝達成分と推定されるセンサー・キナーゼ2種とレスポンス・レギュレーター1種を見い出した。今後は低温センサーとシグナル伝達成分をさらに検索するとともに,低温センサーのタンパク質工学により,温度検知の分子下レベルの解析を行う予定である。

Research Products
(17 results)

All Other

All Publications (17 results)

[Publications] Alia et al.: "Transformation with a gene for choline oxidase enhances the cold tolerance of Arabidopsis during germination and early growth." Plant,Cell & Environment. 21. 232-239 (1998)
[Publications] Alia et al.: "Enhancement of the tolerance of Arabidopsis to high temperatures by genetic engineering of the synthesis of glycinebetaine." The Plant Journal. 16. 155-161 (1998)
[Publications] Fukuchi-Mizutani et al.: "Characterization of △9 acyl-lipid desaturase homologues from Arabidopsis thaliana" Plant and Cell Physiology. 39. 247-253 (1998)
[Publications] Hayashi et al.: "Enhanced germination under high-salt conditions of seeds of transgenic Arabidopsis with a bacterial gene(codA)for choline oxidase." Journal of Plant Research. 111. 357-362 (1998)
[Publications] Kanervo et al.: "Massive breakdown of the photosystem II polypeptides in a mutant of the cyanobacterium Synechocystis sp.PCC6803." Photosynthesis Research. 57. 81-91 (1998)
[Publications] Los & Murata: "Structure and expression of fatty acid desaturases." Biochimica et Biophysica Acta. 1394. 3-15 (1998)
[Publications] Panpoom et al.: "Biochemical characterization of a △12 acyl-lipid desaturase after overexpression of the enzyme in Escherchia coli." Biochimica et Biophysica Acta. 1390. 323-332 (1998)
[Publications] Papageorgiou et al.: "A method to prove the cytoplasmic osmolarity and osmotic water and solute fluxes across the cell membrane of cyanobacteria with chlorophyll a fluorescence: Experiments with Synechococcus sp.PCC7942" Physiologia Plantarum. 103. 215-224 (1998)
[Publications] Sakamoto et al.: "Metabolic engineering of rice leading to biosynthesis of glycinebetaine and tolerance to salt and cold." Plant Molecular Biology. 38. 1011-1019 (1998)
[Publications] Sakamoto et al.: "Alteration of low-temperature susceptibility of the Synechococcus sp.PCC7002 by genetic engineering of membrane lipid unsaturation" Archives of Microbiology. 169. 20-28 (1998)
[Publications] Sippola et al.: "Genetically engineered increase in fatty acid unsaturation in Synechococcus sp.PCC7942 allows D1 protein from exchange and sustenance of photosystem II activity at low temperature." European Journal of Biochemistry. 251. 641-648 (1998)
[Publications] Yokoi et al.: "Introduction of the cDNA for Arabidopsis glycerol-3-phosphate acyltransferase(GPAT)confers unsaturation of fatty acids and chilling tolerance of photosynthesis on rice." Molecular Breeding. 4. 269-275 (1998)
[Publications] Malakhov et al.: "Balanced regulation of expression of the gene for cytochrome cM and that of genes for plastcyanin and cytochrome c6 in Synechocystis" FEBS Letters. 444. 281-284 (1999)
[Publications] Alia et al.: "Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase" Plant Molecular Biology. (印刷中). (1999)
[Publications] Nishiyama et al.: "PsbU,a protein associated with photosystem II,is required for the acquisition of cellular thermotolerance in Synechochoccus species PCC7002" Plant Physiology. (印刷中). (1999)
[Publications] Allakhverdiev et al.: "Alteration of low-temperature sesceptibility of the Synechococcus sp.PCC7002 by genetic engineering of membrane lipid unsaturation." The Proceedings of the National Academy of Sciences,USA. (印刷中). (1999)
[Publications] Sigenthaler & Murata(eds.): "Lipid in Photosynthesis: Structure,Function and Genetics." Kluwer Academic Publishers(Dordrecht,The Netherlands), 321 (1998)

1998 Fiscal Year Annual Research Report

低温適応と低温耐性の分子機構

Principal Investigator

村田 紀夫 岡崎国立共同研究機構, 基礎生物学研究所, 教授 (90011569)

Research Products

[Publications] Alia et al.: "Transformation with a gene for choline oxidase enhances the cold tolerance of Arabidopsis during germination and early growth." Plant,Cell & Environment. 21. 232-239 (1998)

[Publications] Alia et al.: "Enhancement of the tolerance of Arabidopsis to high temperatures by genetic engineering of the synthesis of glycinebetaine." The Plant Journal. 16. 155-161 (1998)

[Publications] Fukuchi-Mizutani et al.: "Characterization of △9 acyl-lipid desaturase homologues from Arabidopsis thaliana" Plant and Cell Physiology. 39. 247-253 (1998)

[Publications] Hayashi et al.: "Enhanced germination under high-salt conditions of seeds of transgenic Arabidopsis with a bacterial gene(codA)for choline oxidase." Journal of Plant Research. 111. 357-362 (1998)

[Publications] Kanervo et al.: "Massive breakdown of the photosystem II polypeptides in a mutant of the cyanobacterium Synechocystis sp.PCC6803." Photosynthesis Research. 57. 81-91 (1998)

[Publications] Los & Murata: "Structure and expression of fatty acid desaturases." Biochimica et Biophysica Acta. 1394. 3-15 (1998)

[Publications] Panpoom et al.: "Biochemical characterization of a △12 acyl-lipid desaturase after overexpression of the enzyme in Escherchia coli." Biochimica et Biophysica Acta. 1390. 323-332 (1998)

[Publications] Papageorgiou et al.: "A method to prove the cytoplasmic osmolarity and osmotic water and solute fluxes across the cell membrane of cyanobacteria with chlorophyll a fluorescence: Experiments with Synechococcus sp.PCC7942" Physiologia Plantarum. 103. 215-224 (1998)

[Publications] Sakamoto et al.: "Metabolic engineering of rice leading to biosynthesis of glycinebetaine and tolerance to salt and cold." Plant Molecular Biology. 38. 1011-1019 (1998)

[Publications] Sakamoto et al.: "Alteration of low-temperature susceptibility of the Synechococcus sp.PCC7002 by genetic engineering of membrane lipid unsaturation" Archives of Microbiology. 169. 20-28 (1998)

[Publications] Sippola et al.: "Genetically engineered increase in fatty acid unsaturation in Synechococcus sp.PCC7942 allows D1 protein from exchange and sustenance of photosystem II activity at low temperature." European Journal of Biochemistry. 251. 641-648 (1998)

[Publications] Yokoi et al.: "Introduction of the cDNA for Arabidopsis glycerol-3-phosphate acyltransferase(GPAT)confers unsaturation of fatty acids and chilling tolerance of photosynthesis on rice." Molecular Breeding. 4. 269-275 (1998)

[Publications] Malakhov et al.: "Balanced regulation of expression of the gene for cytochrome cM and that of genes for plastcyanin and cytochrome c6 in Synechocystis" FEBS Letters. 444. 281-284 (1999)

[Publications] Alia et al.: "Enhanced tolerance to light stress of transgenic Arabidopsis plants that express the codA gene for a bacterial choline oxidase" Plant Molecular Biology. (印刷中). (1999)

[Publications] Nishiyama et al.: "PsbU,a protein associated with photosystem II,is required for the acquisition of cellular thermotolerance in Synechochoccus species PCC7002" Plant Physiology. (印刷中). (1999)

[Publications] Allakhverdiev et al.: "Alteration of low-temperature sesceptibility of the Synechococcus sp.PCC7002 by genetic engineering of membrane lipid unsaturation." The Proceedings of the National Academy of Sciences,USA. (印刷中). (1999)

[Publications] Sigenthaler & Murata(eds.): "Lipid in Photosynthesis: Structure,Function and Genetics." Kluwer Academic Publishers(Dordrecht,The Netherlands), 321 (1998)

村田紀夫岡崎国立共同研究機構, 基礎生物学研究所, 教授 (90011569)