Insulin-like growth factor-1 receptor signaling in 3T3-L1 adipocyte differentiation requires lipid rafts but not caveolae
Insulin-like growth factor-1 receptor signaling in 3T3-L1 adipocyte differentiation requires lipid rafts but not caveolae
复制标题
3T3-L1脂肪细胞分化中的胰岛素样生长因子-1受体信号传导需要脂筏而不是小凹
DOI：
10.1038/sj.cdd.4401405
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发表时间：
2004-07-01
影响因子：
12.4
通讯作者：
Liao, K
中科院分区：
文献类型：
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作者：
Hong, S;Huo, H;Liao, K
以前，我们已经发现在3T3-L1前脂肪细胞分化诱导过程中，脂筏/小窝在胰岛素样生长因子-1(IGF-1)受体信号转导中是必不可少的。然而，目前还不能确定哪些膜脂有序微域介导了受体信号。利用小分子双链RNA干扰(RNAi)成功地抑制了小凹蛋白-1蛋白的表达。在稳定表达小干扰RNA(SiRNA)片段的细胞中，未检测到小窝蛋白-1蛋白或小窝。另一方面，去除小窝蛋白-1并不影响无小窝蛋白的脂筏，也不影响IGF-1受体在脂筏质膜上的定位。在仅有脂筏的RNAi细胞中，IGF-1受体信号转导和诱导细胞分化是正常的。此外，这些IGF-1受体信号事件仍然对胆固醇结合试剂敏感。因此，我们的结果表明，脂筏对IGF-1受体信号转导是足够的，而小凹蛋白-1对信号分子的募集对IGF-1受体信号转导不是必需的。
Previously, we have found that lipid rafts/caveolae were essential for insulin-like growth factor-1 (IGF-1) receptor signaling during 3T3-L1 preadipocytes differentiation induction. However, it was not identified as to which of the membrane lipid-ordered microdomains mediates the receptor signal. Using small double-stranded RNA-mediated interference (RNAi), we successfully suppressed the caveolin-1 protein expression. In cells stably transfected with vector expressing small interfering RNA ( siRNA) fragment, no caveolin-1 protein or caveola was detected. On the other hand, removal of caveolin-1 did not affect the caveolinless lipid rafts or the localization of IGF-1 receptor in lipid rafts on plasma membrane. IGF-1 receptor signal transduction and induced cellular differentiation were normal in RNAi cells with only lipid rafts. Furthermore, these IGF-1 receptor signaling events were still sensitive to the cholesterol-binding reagents. Thus, our results suggest that lipid rafts are sufficient for IGF-1 receptor signaling and the recruitment of signal molecules by caveolin-1 is not essential for IGF-1 receptor signaling.