The linoleic acid derivative DCP-LA selectively activates PKC-ε, possibly binding to the phosphatidylserine binding site
The linoleic acid derivative DCP-LA selectively activates PKC-ε, possibly binding to the phosphatidylserine binding site
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DOI：
10.1194/jlr.m500329-jlr200
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发表时间：
2006-06-01
影响因子：
6.5
通讯作者：
Nishizaki, Tomoyuki
中科院分区：
文献类型：
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作者：
Kanno, Takeshi;Yamamoto, Hideyuki;Nishizaki, Tomoyuki
研究了8-[2-（2-戊基环丙基甲基）环丙基]-辛酸（DCP-LA）对蛋白激酶C（PKC）活性的影响。在反相高效液相色谱原位PKC测定中，DCP-LA以浓度依赖性（10 nM-100 μ M）方式显著激活PC-12细胞中的PKC，在100 nM时具有最大效应，并且DCP-LA效应被PKC抑制剂GF 109203 X或新型PKC同工酶PKC-L1的选择性抑制肽阻断。此外，DCP-LA激活HEK-293细胞中的PKC，其被针对PKC-β的小干扰RNA抑制。在无细胞PKC测定中，在这里检查的九种同工酶中，在不存在二油酰-磷脂酰丝氨酸和1，2-二油酰-sn-甘油的情况下，DCP-LA最强烈地激活PKC-β，具有超过其他PKC同工酶的> 7倍效力;相反，DCP-LA作用被二油酰-磷脂酰丝氨酸抑制。DCP-LA也激活PKC-γ（一种常规PKC），但与PKC-γ相比，其激活程度要小得多，其机制与PKC-γ激活不同。因此，DCP-LA可能通过与PKC-β上的磷脂酰丝氨酸结合位点结合而作为PKC-β的选择性激活剂。这些结果可能为PKC激活中的脂质信号提供新的见解。
This study examined the effect of 8-[2-(2-pentylcyclopropylmethyl)cyclopropyl]-octanoic acid (DCP-LA), a newly synthesized linoleic acid derivative with cyclopropane rings instead of cis-double bonds, on protein kinase C (PKC) activity. In the in situ PKC assay with reverse-phase high-performance liquid chromatography, DCP-LA significantly activated PKC in PC-12 cells in a concentration-dependent (10 nM-100 mu M) manner, with the maximal effect at 100 nM, and the DCP-LA effect was blocked by GF109203X, a PKC inhibitor, or a selective inhibitor peptide of the novel PKC isozyme PKC-epsilon. Furthermore, DCP-LA activated PKC in HEK-293 cells that was inhibited by the small, interfering RNA against PKC-epsilon. In the cell-free PKC assay, of the nine isozymes examined here, DCP-LA most strongly activated PKC-epsilon, with > 7-fold potency over other PKC isozymes, in the absence of dioleoyl-phosphatidylserine and 1,2-dioleoyl-sn-glycerol; instead, the DCP-LA action was inhibited by dioleoyl-phosphatidylserine. DCP-LA also activated PKC-gamma, a conventional PKC, but to a much lesser extent compared with that for PKC-epsilon, by a mechanism distinct from PKC-epsilon activation. Thus, DCP-LA serves as a selective activator of PKC-epsilon, possibly by binding to the phosphatidylserine binding site on PKC-epsilon. These results may provide fresh insight into lipid signaling in PKC activation.