Multiple non-specific effects of sphingosine on adenylate cyclase and cyclic AMP accumulation in S49 lymphoma cells preclude its use as a specific inhibitor of protein kinase C.
Multiple non-specific effects of sphingosine on adenylate cyclase and cyclic AMP accumulation in S49 lymphoma cells preclude its use as a specific inhibitor of protein kinase C.
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鞘氨醇对 S49 淋巴瘤细胞中腺苷酸环化酶和环 AMP 积累的多种非特异性影响使其无法用作蛋白激酶 C 的特异性抑制剂。
DOI：
10.1042/bj2680507
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Clark,RB
中科院分区：
文献类型：
--
作者：
Johnson,JA;Clark,RB
最近的研究表明，佛波醇酯，蛋白激酶C（PKC）可能在哺乳动物细胞中的腺苷酸环化酶的调节中发挥作用。由于D-鞘氨醇已被报道在许多细胞类型中特异性抑制PKC，我们评估了其对肾上腺素刺激S49淋巴瘤细胞中环AMP积累的影响。我们发现鞘氨醇具有多种非特异性作用，这不能通过抑制PKC来解释。这些影响包括：（i）鞘氨醇的抑制（50 μ M）肾上腺素刺激的细胞的环AMP积累和鞘氨醇渗透，使它们泄漏ATP;（iii）鞘氨醇（20 microMs）肾上腺素刺激的环AMP积累的增加;（iii）在离体膜中，鞘氨醇对肾上腺素刺激的腺苷酸环化酶的抑制高达95%;和（iv）鞘氨醇（20 μ M）抑制环磷酸腺苷消除的细胞机制。这些结果表明，在得出结论认为鞘氨醇的作用是特异性抑制PKC的结果之前，评价鞘氨醇的非特异性作用是非常重要的。
Recent studies with phorbol esters have suggested that protein kinase C (PKC) may play a role in the regulation of adenylate cyclase in mammalian cells. Since D-sphingosine has been reported to specifically inhibit PKC in many cell types, we evaluated its effects on stimulation of cyclic AMP accumulation by adrenaline in S49 lymphoma cells. We found sphingosine to have multiple non-specific effects which could not be explained by an inhibition of PKC. These effects included: (i) inhibition by sphingosine (50 microM) of adrenaline-stimulated cyclic AMP accumulation and sphingosine permeation of the cells which rendered them leaky to ATP; (iii) sphingosine (20 microMs) augmentation of adrenaline-stimulated cyclic AMP accumulation; (iii) inhibition by sphingosine of adrenaline-stimulated adenylate cyclase in isolated membranes by up to 95%; and (iv) sphingosine (20 microM) inhibition of cellular mechanisms for the elimination of cyclic AMP. These results demonstrate the importance of evaluating the non-specific effects of sphingosine before concluding that its actions are the consequences of a specific inhibition of PKC.