{"created":"2023-07-27T06:44:29.129260+00:00","id":34726,"links":{},"metadata":{"_buckets":{"deposit":"53275610-a9c4-4b9e-a6ca-a563b9c64185"},"_deposit":{"created_by":3,"id":"34726","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"34726"},"status":"published"},"_oai":{"id":"oai:kanazawa-u.repo.nii.ac.jp:00034726","sets":["2812:2813:2826"]},"author_link":["15508"],"item_9_biblio_info_8":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2009-01-01","bibliographicIssueDateType":"Issued"},"bibliographicPageStart":"13p.","bibliographicVolumeNumber":"2006-2007","bibliographic_titles":[{"bibliographic_title":"平成19(2007)年度 科学研究費補助金 基盤研究(C) 研究成果報告書"},{"bibliographic_title":"2007 Fiscal Year Final Research Report","bibliographic_titleLang":"en"}]}]},"item_9_creator_33":{"attribute_name":"著者別表示","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{}],"nameIdentifiers":[{},{},{},{}]}]},"item_9_description_21":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"陸棲ラン藻Nostoc communen(和名:イシクラゲ)が示す極限的な乾燥耐性の分子機構を解明するために、本研究課題では細胞内で働いている要素に着目して研究した。本研究経費によってエバポレイティブ光散乱検出器を導入することのよってトレハロースを定量できるようにした。乾燥したイシクラゲはトレハロースを蓄積していたが、吸水することによってトレハロース量は低下し、完全に水和したコロニーでは検出されなかった。コロニーの水分含量に応答してトレハロース量が調節されていることを示す。乾燥ストレスによってトレハロースが蓄積される機構を明らかにするために、トレハロース合成酵素およびトレハロース加水分解酵素(トレハラーゼ)の活性制御を解析した。イシクラゲにおいてトレハロース合成酵素遺伝子treZ、treY、およびトレハラーゼ遺伝子treHがひとつの転写単位を構成していた。これらの遺伝子の転写産物量は乾燥ストレス処理によって大きく変化することはなく、転写レベルの制御ではないことが示された。生化学的解析を行なったところ、トレハロース合成酵素は反応溶液中の塩濃度に影響されず高い活性を示したが、トレハラーゼは塩濃度の上昇に伴って活性が阻害されることが分かった。トレハラーゼがトレハロース量の調節において鍵酵素として働いており、乾燥ストレス下で活性が阻害され、トレハロースの合成量が相対的に高くなることが重要であることを示唆する。細胞外基質に存在する可溶性タンパク質を解析した。β-グルコシダーゼを精製しアミノ末端配列解析を行なったところ、ファシクリンタンパク質と相同性を示すことが分かった。イシクラゲに特徴的なタンパク質として知られているWspAを精製し酵素活性を調べたところβ-ガラクトシダーゼ活性を示すことが分かった。これらのタンパク質は細胞外基質において重要な役割をもつと考えられる。","subitem_description_type":"Abstract"},{"subitem_description":"We investigated changes of trehalose level in field-isolated, natural colonies of the terrestrial cyanobacterium Nostoc commune responding to desiccation. No detectable trehalose was found in fully hydrated N. commune colonies; however, trehalose accumulation occurred in response to water loss during desiccation and high levels of trehalose were detected in the air-dried colonies. The three genes for trehalose metabolism, treZ (maltooligosyltrehalose trehalohydrolase, Mth), treY (maltooligosyltrehalose synthase, Mts), and treH (trehalase), were found as a gene cluster, and the mRNAs for these genes were detectable at similar levels during desiccation. Trehalase of N. punctiforme was heterologously expressed in E. coli cells in an active form with a molecular mass of 52kDa. Trehalase activity was strongly inhibited in the presence of 10mM NaCl while trehalose synthesis activity remained active in the presence of salt. These data suggest that the rate of trehalose production exceeds that of trehalose hydrolysis under water-stress conditions characterized by increased cellular solute concentrations. The terrestrial cyanobacterium N. commune forms a visible colony in which the cells are embedded in extracellular polysaccharides (EPSs), which play a crucial role in the extreme desiccation tolerance of this organism. The activities that hydrolyse glycoside bonds were examined using artificial nitrophenyl-linked sugars as substrates. Aβ-D-glucosidase, with a molecular mass of20kDa, was resistant to20min of boiling and was identified as a cyanobacterial fasciclin protein based on its N-terminal amino-acid sequence. The36-kDa major protein (WspA) showed heat-resistantβ-D-galactosidase activity.","subitem_description_type":"Abstract"}]},"item_9_description_22":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"研究課題/領域番号:18608001, 研究期間(年度):2006–2007","subitem_description_type":"Other"},{"subitem_description":"出典：「陸棲ラン藻における極限的な乾燥耐性の分子機構」研究成果報告書　課題番号18608001\n  (KAKEN：科学研究費助成事業データベース（国立情報学研究所）)\n　　　本文データは著者版報告書より作成","subitem_description_type":"Other"}]},"item_9_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.24517/00034713","subitem_identifier_reg_type":"JaLC"}]},"item_9_publisher_17":{"attribute_name":"公開者","attribute_value_mlt":[{"subitem_publisher":"金沢大学自然システム学系"}]},"item_9_relation_28":{"attribute_name":"関連URI","attribute_value_mlt":[{"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/search/?qm=70324069","subitem_relation_type_select":"URI"}},{"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18608001/","subitem_relation_type_select":"URI"}},{"subitem_relation_type_id":{"subitem_relation_type_id_text":"https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-18608001/186080012007kenkyu_seika_hokoku_gaiyo/","subitem_relation_type_select":"URI"}}]},"item_9_version_type_25":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-10-05"}],"displaytype":"detail","filename":"SC-PR-SAKAMOTO-T-kaken 2009-13p.pdf","filesize":[{"value":"523.0 kB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"SC-PR-SAKAMOTO-T-kaken 2009-13p.pdf","url":"https://kanazawa-u.repo.nii.ac.jp/record/34726/files/SC-PR-SAKAMOTO-T-kaken 2009-13p.pdf"},"version_id":"25cd8d48-7b04-4fd9-bc16-3aa9c0d1f502"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"research report","resourceuri":"http://purl.org/coar/resource_type/c_18ws"}]},"item_title":"陸棲ラン藻における極限的な乾燥耐性の分子機構","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"陸棲ラン藻における極限的な乾燥耐性の分子機構"},{"subitem_title":"Molecular mechanisms of extreme desiccation tolerance in the terrestrial cyanobacterium","subitem_title_language":"en"}]},"item_type_id":"9","owner":"3","path":["2826"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-10-05"},"publish_date":"2017-10-05","publish_status":"0","recid":"34726","relation_version_is_last":true,"title":["陸棲ラン藻における極限的な乾燥耐性の分子機構"],"weko_creator_id":"3","weko_shared_id":3},"updated":"2023-07-27T14:24:54.145254+00:00"}