Characterization of the interaction of ingenol 3-angelate with protein kinase C
Characterization of the interaction of ingenol 3-angelate with protein kinase C
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DOI：
10.1158/0008-5472.can-03-3403
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发表时间：
2004-05-01
期刊：
影响因子：
11.2
通讯作者：
Blumberg, PM
中科院分区：
文献类型：
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作者：
Kedei, N;Lundberg, DJ;Blumberg, PM
吲哚-3-天使酸酯(I3A)是一品红的有效成分之一。它已经被用于传统医学。在这里，我们报告了I3A作为蛋白激酶C(PKC)配体的初步特征。在高亲和力的磷脂酰丝氨酸存在下，I3A与PKC-α结合；然而，在这种检测条件下，几乎没有观察到PKC异构体的选择性。PKC亚型对下调表现出不同的敏感性和选择性。I3A和佛波酯(PMA)在WEHI-231、HOP-92和COLO-205细胞中的表达。在所有三种细胞类型中，I3A抑制细胞增殖的效力略低于PMA。在完整的CHO-K1细胞中，I3A能够以与PMA相同或更高的效力移位不同的绿色荧光蛋白标记的PKC亚型，通过共聚焦显微镜观察到。尤其是PKC-Delta对I3A和PMA的反应表现出不同的易位模式。在WEHI-231细胞中，与PMA相比，I3A诱导炎性细胞因子IL-6的分泌水平更高，并且呈现明显的双相剂量-反应曲线。与PMA或生理调节剂二酰甘油相比，I3A不能引起PKC-Delta的C1b结构域与脂质的相同程度的结合，并能够部分阻断这些药物诱导的结合，通过表面等离子共振测量。I3A诱导的PKC-a活性低于PMA诱导的PKC-a活性。I3A的新的行为模式使其成为进一步评估的极大兴趣。
Ingenol 3-angelate (I3A) is one of the active ingredients in Euphorbia peplus. which has been used in traditional medicine. Here, we report the initial characterization of I3A as a protein kinase C (PKC) ligand. I3A bound to PKC-alpha in the presence of phosphatidylserine with high affinity; however, under these assay conditions, little PKC isoform selectivity was observed. PKC isoforms did show different sensitivity and selectivity for down-regulation by. I3A and phorbol 12-myristate 13-acetate (PMA) in WEHI-231, HOP-92, and Colo-205 cells. In all of the three cell types, I3A inhibited cell proliferation with somewhat lower potency than did PMA. In intact CHO-K1 cells, I3A was able to translocate different green fluorescent protein-tagged PKC isoforms, visualized by confocal microscopy, with equal or higher potency than PMA. PKC-delta in particular showed a different pattern of translocation in response to I3A and PMA. I3A induced a higher level of secretion of the inflammatory cytokine interleukin 6 compared with PMA in the WEHI-231 cells and displayed a marked biphasic dose-response curve for the induction. I3A was unable to cause the same extent of association of the C1b domain of PKC-delta with lipids, compared with PMA or the physiological regulator diacylglycerol, and was able to partially block the association induced by these agents, measured by surface plasmon resonance. The in vitro kinase activity of PKC-a induced by I3A was lower than that induced by PMA. The novel pattern of behavior of I3A makes it of great interest for further evaluation.