哺乳類のNa+依存型L-アスコルビック酸トランスポーターの一族
H Tsukaguchi1, T Tokui, B Mackenzie
1Membrane Biology Program, Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|May 20, 1999
まとめ
研究者らは,体内のビタミンCレベルを調節するために重要な2つの新しいビタミンCトランスポーター,SVCT1とSVCT2を特定しました. これらのトランスポーターは,細胞が酵素反応と抗酸化物質の保護に不可欠な十分なビタミンCを受け取ることを保証します.
科学分野:
- バイオケミストリー バイオケミストリー
- 細胞生物学 細胞生物学
- 生理学 生理学とは
背景:
- ビタミンC (L-アスコルビン酸) は,酵素反応と抗酸化防御に不可欠です.
- 現在の理解からすると,糖質トランスポーター (GLUT) は,ビタミンCのプラズマ形態のため,ビタミンCの吸収に非効率的であることが示唆されています.
- 特定のビタミンCトランスポーターの調査は,ビタミンCの規制を理解するための鍵です.
研究 の 目的:
- L-アスコルビン酸のための新しいトランスポーターを分離し,特徴づけること.
- ビタミンCの吸収と代謝におけるこれらのトランスポーターの役割を調査する.
- L-アスコルビック酸輸送の分布と生理学的重要性を理解するために.
主な方法:
- ネズミのcDNAライブラリから2つのL-アスコルビン酸トランスポーター (SVCT1とSVCT2) を分離した.
- トランスポーター活動の機能的特徴,親和性およびステレオ特異性を含む.
- SVCT1およびSVCT2イソフォームの組織分布の分析.
主要な成果:
- L-アスコルビン酸の2つの異なるトランスポーター,SVCT1とSVCT2が特定されました.
- 両方のトランスポーターは,Na+電化学的梯度によって誘発される高親和性,濃縮性L-アスコルビック酸の吸収を媒介する.
- SVCT1は主に上皮系に存在し,SVCT2は代謝活性細胞および特殊組織に存在します.
結論:
- SVCT1とSVCT2は,L-アスコルビック酸輸送の主要な媒介体である.
- SVCT1とSVCT2の異なる組織分布は,ビタミンCホメオスタシスの特殊な役割を示唆しています.
- これらのトランスポーターを理解することは,ビタミンCの供給と代謝の調節に不可欠です.
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