Exclusive Expression of Transketolase in the Vanadocytes of the Vanadium-Rich Ascidian, Ascidia sydneiensis samea
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ID | 23 |
本文ファイル | |
著者 |
Uyama, Taro
Kanamori, Kan
Michibata, Hitoshi
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キーワード | Chordates
Metal Accumulation
Redox
Gene Expression
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NDC |
生物科学・一般生物学
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抄録(英) | Ascidians, especially those belonging to the Ascidiidae, are known to accumulate extremely high levels of vanadium in vanadocytes, one type of blood (coelomic) cell. Vanadium, which exists in the +5 oxidation state in seawater, is accumulated in the vanadocytes and reduced to the +3 oxidation state. We have been trying to characterize all of the polypeptides specific to vanadocytes and to specify the proteins that participate in the accumulation and reduction of vanadium. To date, we have localized three enzymes in vanadocytes: 6-phosphogluconate dehydrogenase (6-PGDH: EC 1.1.1.44), glucose-6-phosphate dehydrogenase (G6PDH: EC 1.1.1.49), and glycogen phosphorylase (GP: EC 2.4.1.1), all of which are involved in the pentose phosphate pathway. In the current study, we cloned a cDNA for transketolase, an essential and rate-limiting enzyme in the non-oxidative part of the pentose phosphate pathway, from vanadocytes. The cDNA encoded a protein of 624 amino acids, which showed 61.8 0dentity to the human adult-type transketolase gene product. By immunocytochemistry and immunoblot analyses, the transketolase was revealed to be a protein that was expressed only in vanadocytes and not in any of the more than ten other types of blood cell. This finding, taken together with the localized expression of the other three enzymes, strongly supports the hypothesis that the pentose phosphate pathway functions exclusively in vanadocytes.
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掲載誌名 |
Biochimica et biophysica acta
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巻 | 1494巻
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開始ページ | 83
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終了ページ | 90
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出版年月日 | 2000
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出版者 | Elsevier Science B.V.
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ISSN | 0167-4781
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NCID | |
出版者DOI | |
PubMedID | |
言語 |
英語
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NII資源タイプ |
学術雑誌論文
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広大資料タイプ |
学術雑誌論文
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DCMIタイプ | text
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フォーマット | application/pdf
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著者版フラグ | author
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権利情報 | Copyright (c) 2000 Elsevier Science B.V.
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関連情報URL(IsVersionOf) | http://dx.doi.org/10.1016/S0167-4781(00)00222-0
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部局名 |
理学研究科
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