| Item type |
学術雑誌論文 / Journal Article_02(1) |
| 公開日 |
2009-03-11 |
| タイトル |
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タイトル |
Critical Role of Glu^<40>-Ser^<48> Loop Linking Actuator Domain and First Transmembrane Helix of Ca^<2+>-ATPase in Ca^<2+> Deocclusion and Release from ADP-insensitive Phosphoenzyme |
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言語 |
en |
| 言語 |
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言語 |
eng |
| 資源タイプ |
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資源タイプ |
journal article |
| 著者 |
大保, 貴嗣
Yamasaki, K
Danko, S
Suzuki, H
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| 著者 ローマ字 |
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Daiho, T |
| 書誌情報 |
Journal of Biological Chemistry
巻 282,
号 47,
p. 34429-34447,
発行日 2007-11-01
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| ISSN |
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収録物識別子タイプ |
ISSN |
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収録物識別子 |
0021-9258 |
| DOI |
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関連タイプ |
isVersionOf |
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識別子タイプ |
DOI |
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関連識別子 |
10.1074/jbc.M707665200 |
| リンクURL |
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内容記述タイプ |
Other |
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内容記述 |
http://www.ncbi.nlm.nih.gov/pubmed?term=Critical%20Role%20of%20Glu^%3C40%3E-Ser^%3C48%3E%20Loop%20Linking%20Actuator%20Domain%20and%20First%20Transmembrane%20Helix%20of%20Ca^%3C2%2B%3E-ATPase%20in%20Ca^%3C2%2B%3E%20Deocclusion%20and%20Release%20from%20ADP-insensitive%20Phosphoenzyme | http://www.ncbi.nlm.nih.gov/pubmed?term=Critical%20Role%20of%20Glu^%3C40%3E-Ser^%3C48%3E%20Loop%20Linking%20Actuator%20Domain%20and%20First%20Transmembrane%20Helix%20of%20Ca^%3C2%2B%3E-ATPase%20in%20Ca^%3C2%2B%3E%20Deocclusion%20and%20Release%20from%20ADP-insensitive%20Phosphoenzyme |
| 抄録 |
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内容記述タイプ |
Abstract |
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内容記述 |
Functional importance of the length of the A/M1-linker (Glu^<40>-Ser^<48>) connecting the Actuator domain and 1st transmembrane helix of sarcoplasmic reticulum Ca^<2+>-ATPase was explored by its elongation with glycines-insertion at Pro^<42>/Ala^<43> and Gly^<46>/Lys^<47>. Two or more glycines-insertion at each site completely abolished ATPase activity. The isomerization of phosphoenzyme intermediate (EP) from the ADP-sensitive form (E1P) to ADP-insensitive form (E2P) was markedly accelerated but the decay of EP was completely blocked in these mutants. E2P thus accumulated was demonstrated to be E2PCa_2 possessing two occluded Ca^<2+> ions at the transport sites, and the Ca^<2+> deocclusion and release into lumen was blocked in the mutants. By contrast, the hydrolysis of theCa^<2+>-free form of E2P produced from P_I without Ca^<2+> was as rapid in the mutants as in the wild type. Analysis of resistance against trypsin and proteinase K revealed that the structure of E2PCa_2 accumulated is an intermediate state between the E1PCa_2 and Ca^<2+>-released E2P states. Namely, in E2PCa_2, the Actuator domain is already largely rotated from its position in E1PCa_2 and associated with the Phosphorylation domain as in the Ca^<2+>-released E2P state,however in E2PCa_2 the hydrophobic interactions among these domains and Leu^<119>/Tyr^<122> on the top of 2nd transmembrane helix is not formed properlyyet. This is consistent with our previous finding that these interactions at Tyr^<122> are critical for formation of Ca^<2+>-released E2P structure. Results showed that the EP isomerization/Ca^<2+>-release process consists of two steps; E1PCa_2 → E2PCa_2 → E2P + 2Ca^<2+>, and the intermediate state E2PCa_2 was identified for the first time. Results further indicated that the A/M1-linker with its appropriately short length, probably because of the strain imposed in E2PCa_2, is critical for the correct positioning and interactions of the Actuator and Phosphorylation domains to cause structural changes for the Ca^<2+> deocclusion and release. |
| 注記 |
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内容記述タイプ |
Other |
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注記 |
author |
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内容記述タイプ |
Other |
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資源タイプ |
text |
| 著者版フラグ |
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出版タイプ |
AM |
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内容記述タイプ |
Other |
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内容記述 |
application/pdf |
| ID(XooNIps) |
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17881350 |
| 閲覧数(XooNIps) |
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| ダウンロード数(XooNIps) |
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2627 |
1606.pdf (4.1 MB)
