Fujimura Yoshinori, Yamada Koji, Tachibana Hirofumi
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Biochem Biophys Res Commun. 2005 Oct 21;336(2):674-81. doi: 10.1016/j.bbrc.2005.08.146.
(-)-Epigallocatechin-3-O-gallate (EGCG), a major green tea polyphenol, has previously exhibited a suppressive effect on the expression of the high-affinity IgE receptor (FcepsilonRI). This effect has been shown to be elicited by interaction with the plasma membrane microdomain lipid rafts. Recently, we have identified the 67 kDa laminin receptor (67LR) as a cell surface EGCG receptor that mediates an anti-cancer action. Here we show that the 67LR is highly associated with lipid rafts on human basophilic KU812 cells. Experiments using 67LR-enhanced and -reduced cells revealed that the EGCG's ability to downregulate FcepsilonRI expression correlated with the amount of 67LR. Thus, these results suggest that the lipid raft-associated 67LR plays an important role in mediating the FcepsilonRI-suppressive action of EGCG.
（-）-表没食子儿茶素-3-O-没食子酸酯（EGCG）是绿茶中的一种主要多酚类物质，此前已被证明对高亲和力IgE受体（FcepsilonRI）的表达具有抑制作用。这种作用已被证明是通过与质膜微区脂筏相互作用而引发的。最近，我们已确定67 kDa层粘连蛋白受体（67LR）是一种介导抗癌作用的细胞表面EGCG受体。在此我们表明，67LR与人类嗜碱性KU812细胞上的脂筏高度相关。使用67LR增强和减少的细胞进行的实验表明，EGCG下调FcepsilonRI表达的能力与67LR的量相关。因此，这些结果表明，与脂筏相关的67LR在介导EGCG对FcepsilonRI的抑制作用中起重要作用。
