Protein kinase C isoform antagonism controls BNaC2 (ASIC1) function
Protein kinase C isoform antagonism controls BNaC2 (ASIC1) function
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DOI：
10.1074/jbc.m208995200
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发表时间：
2002-11-29
影响因子：
4.8
通讯作者：
Benos, DJ
中科院分区：
文献类型：
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作者：
Berdiev, BK;Xia, JZ;Benos, DJ
我们探讨了蛋白激酶C（PKC）及其亚型的参与BNaC 2的调节。在mRNA水平上对PKC亚型表达的逆转录酶PCR评价显示，在所有分析的胶质瘤细胞系中存在α和β/β ';大多数但不是所有细胞系表达δ和ζ。在肿瘤细胞中未发现PKC β I和β II亚型的信息。正常星形胶质细胞表达β，但不表达γ。这些结果的基本特征在蛋白质水平上通过Western分析得到证实。这种在神经胶质瘤细胞系中PKC亚型表达的不成比例的模式进一步反映在这些PKC亚型对BNaC 2活性在双层中的功能性影响中。PKC全酶或PKC β I和PKC β II亚型的组合抑制BNaC 2。PKC β和PKCzeta或它们的组合对双层中的BNaC 2活性都没有任何影响。PKC β I和PKC β II混合物对BNaC 2活性的抑制作用被5倍过量的PKC β I和PKC β II组合消除。PKC全酶、PKC β I、PKC β II、PKC δ、PKC β 2和PKC β 3在体外磷酸化BNaC 2。在膜片钳实验中，PKC β I和PKC β II的组合抑制了基础激活的内向Na+电导。PKC同种型的可变表达及其在调节BNaC 2活性中的功能性拮抗作用支持多个PKC同种型的参与有助于BNaC 2的总体活性的想法。
We explored the involvement of protein kinase C (PKC) and its isoforms in the regulation of BNaC2. Reverse transcriptase PCR evaluation of PKC isoform expression at the level of mRNA revealed the presence of alpha and epsilon/epsilon' in all glioma cell lines analyzed; most, but not all cell lines expressed delta and zeta. No messages were found for the betaI and betaII isotypes of PKC in the tumor cells. Normal astrocytes expressed beta but not gamma. The essential features of these results were confirmed at the protein level by Western analysis. This disproportionate pattern of PKC isoform expression in glioma cell lines was further echoed in the functional effects of these PKC isoforms on BNaC2 activity in bilayers. PKC holoenzyme or the combination of PKCbetaI and PKCbetaII isoforms inhibited BNaC2. Neither PKCepsilon nor PKCzeta or their combination had any effect on BNaC2 activity in bilayers. The inhibitory effect of the PKCbetaI and PKCbetaII mixture on BNaC2 activity was abolished by a 5-fold excess of a PKCepsilon and PKCzeta combination. PKC holoenzymes, PKCbetaI, PKCbetaII, PKCdelta, PKCepsilon, and PKCzeta phosphorylated BNaC2 in vitro. In patch clamp experiments,the combination of PKCbetaI and PKCbetaII inhibited the basally activated inward Na+ conductance. The variable expression of the PKC isotypes and their functional antagonism in regulating BNaC2 activity support the idea that the participation of multiple PKC isotypes contributes to the overall activity of BNaC2.