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イタノ ナオキ
ITANO NAOKI
板野 直樹 所属 京都産業大学 生命科学部 先端生命科学科 職種 教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2014/01 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 標題 | Effect of a cholesterol-rich lipid environment on the enzymatic activity of reconstituted hyaluronan synthase |
| 執筆形態 | その他 |
| 掲載誌名 | BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS |
| 出版社・発行元 | ACADEMIC PRESS INC ELSEVIER SCIENCE |
| 巻・号・頁 | 443(2),pp.666-671 |
| 著者・共著者 | Pawared Ontong,Yasuyo Hatada,Shun'ichiro Taniguchi,Ikuko Kakizaki,Naoki Itano |
| 概要 | Hyaluronan synthase (HAS) is a unique membrane-associated glycosyltransferase and its activity is lipid dependent. The dependence however is not well understood, especially in vertebrate systems. Here we investigated the functional association of hyaluronan synthesis in a cholesterol-rich membrane-environment. The culture of human dermal fibroblasts in lipoprotein-depleted medium attenuated the synthesis of hyaluronan. The sequestration of cellular cholesterol by methyl-beta-cyclodextrin also decreased the hyaluronan production of fibroblasts, as well as the HAS activity. To directly evaluate the effects of cholesterol on HAS activity, a recombinant human HAS2 protein with a histidine-tag was expressed as a membrane protein by using a baculovirus system, then successfully solubilized, and isolated by affinity chromatography. When the recombinant HAS2 proteins were reconstituted into liposomes composed of both saturated phosphatidylcholine and cholesterol, this provided a higher enzyme activity as compared with the liposomes formed by phosphatidylcholine alone. Cholesterol regulates HAS2 activity in a biphasic manner, depending on the molar ratio of phosphatidylcholine to cholesterol. Furthermore, the activation profiles of different lipid compositions were determined in the presence or absence of cholesterol. Cholesterol had the opposite effect on the HAS2 activity in liposomes composed of phosphatidylethanolamine or phosphatidylserine. Taken together, the present data suggests a clear functional association between HAS activity and cholesterol-dependent alterations in the physical and chemical properties of cell membranes. (C) 2013 Elsevier Inc. All rights reserved. |
| DOI | 10.1016/j.bbrc.2013.12.028 |
| ISSN | 0006-291X/1090-2104 |