N,N-dimethylsphingosine is a potent competitive inhibitor of sphingosine kinase but not of protein kinase C:: Modulation of cellular levels of sphingosine 1-phosphate and ceramide
N,N-dimethylsphingosine is a potent competitive inhibitor of sphingosine kinase but not of protein kinase C:: Modulation of cellular levels of sphingosine 1-phosphate and ceramide
复制标题
DOI：
10.1021/bi980744d
复制
发表时间：
1998-09-15
期刊：
影响因子：
2.9
通讯作者：
Spiegel, S
中科院分区：
文献类型：
--
作者：
Edsall, LC;Van Brocklyn, JR;Spiegel, S
1-磷酸鞘氨醇（SPP）是由鞘氨醇激酶作用形成的脂质第二信使，参与调节多种生物过程，包括生长、存活和分化。N，N-二甲基鞘氨醇（DMS）对鞘氨醇激酶有抑制作用，已被用于研究SPP的生物学作用，但DMS抑制鞘氨醇激酶的机制尚不清楚。此外，DMS已被证明在体外抑制蛋白激酶C。在这里，我们报告说，DMS是一个竞争性抑制剂的鞘氨醇激酶从U937单核细胞白血病细胞，瑞士3 T3成纤维细胞，和PC 12嗜铬细胞瘤细胞。DMS降低SPP的基础水平，并防止SPP响应于已知激活鞘氨醇激酶的生理刺激而增加。DMS还有效地增加了各种细胞类型中神经酰胺的细胞水平，并且神经酰胺/SPP变阻器的重置可以解释DMS的促凋亡作用。此外，DMS在有效抑制鞘氨醇激酶的浓度下，对蛋白激酶C活性或其膜转位没有影响。因此，DMS在不同的细胞类型中充当鞘氨醇激酶的特异性竞争性抑制剂，并且是阐明SPP作为细胞内第二信使的作用的有用工具。
Sphingosine 1-phosphate (SPP), a lipid second messenger formed by the action of sphingosine kinase, has been implicated in regulating diverse biological processes, including growth, survival, and differentiation. N,N-Dimethylspingosine (DMS) inhibits sphingosine kinase and has been used to investigate the biological roles of SPP; however, little is known of the mechanism of inhibition of sphingosine kinase by DMS. In addition, DMS has been shown to inhibit protein kinase C in vitro. Here we report that DMS is a competitive inhibitor of sphingosine kinase from U937 monoblastic leukemia cells, Swiss 3T3 fibroblasts, and PC12 pheochromocytoma cells. DMS decreases basal levels of SPP and prevents increases in SPP in response to physiological stimuli known to activate sphingosine kinase. DMS also effectively increases cellular levels of ceramide in a variety of cell types, and resetting of the ceramide/SPP rheostat may account for the pro-apoptotic effects of DMS. Moreover, DMS, at concentrations which effectively inhibit sphingosine kinase, has no effect on protein kinase C activity or its membrane translocation. Thus, DMS acts as a specific competitive inhibitor of sphingosine kinase in diverse cell types and is a useful tool to elucidate the role of SPP as an intracellular second messenger.