Yu C L, Tsai M H, Stacey D W
Department of Molecular Biology, Cleveland Clinic Foundation, Ohio 44106.
Mol Cell Biol. 1990 Dec;10(12):6683-9. doi: 10.1128/mcb.10.12.6683-6689.1990.
Quiescent NIH 3T3 cells were stimulated with serum prior to the extraction of total cellular lipids. These lipids were fractionated on thin-layer chromatography plates, and individual fractions were tested for the ability to inhibit GTPase-activating protein (GAP) activity. Two separate GAP inhibitory lipids were produced. One behaved similarly to arachidonic acid during silica gel chromatography, whereas the other was related to a phosphoinositide. Further study of the arachidonic acid-related material indicated that it was produced between 1 and 5 min after serum addition but was never observed in high-density, contact-inhibited cultures. The identity of these lipids is under investigation. The possibility raised by these results, that a metabolite of arachidonic acid is involved in mitogenic signaling, was supported by the finding that several lipoxygenase products of arachidonic acid efficiently inhibited GAP activity. These results provide further support for the hypothesis that lipids, GAP, and ras activity function together in the control of cellular proliferation.
在提取总细胞脂质之前，用血清刺激静止的NIH 3T3细胞。这些脂质在薄层层析板上进行分离，然后测试各个组分抑制GTP酶激活蛋白（GAP）活性的能力。产生了两种不同的GAP抑制脂质。一种在硅胶层析过程中的行为与花生四烯酸相似，而另一种与磷酸肌醇有关。对花生四烯酸相关物质的进一步研究表明，它在添加血清后1至5分钟之间产生，但在高密度、接触抑制的培养物中从未观察到。这些脂质的身份正在研究中。这些结果提出了花生四烯酸的一种代谢产物参与有丝分裂信号传导的可能性，这一可能性得到了以下发现的支持：花生四烯酸的几种脂氧合酶产物能有效抑制GAP活性。这些结果为脂质、GAP和ras活性在细胞增殖控制中共同发挥作用的假说提供了进一步的支持。
