Interaction of P-glycoprotein with protein kinase C in human multidrug resistant carcinoma cells.
Interaction of P-glycoprotein with protein kinase C in human multidrug resistant carcinoma cells.
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发表时间：
1996-08
期刊：
影响因子：
11.2
通讯作者：
J. Yang;K. Chin;W. Hait
中科院分区：
文献类型：
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作者：
J. Yang;K. Chin;W. Hait
间接证据表明，多药转运蛋白p -糖蛋白（P-gp）被蛋白激酶C （PKC）磷酸化，磷酸化调节其转运功能。更直接地说明第一个前提。我们研究了P-gp与PKC在MCF-7和KB敏感和多药耐药人癌细胞系中的相互作用。我们发现多重耐药细胞系MCF-7/AdrR和KB-V-1使用任一蛋白的抗体共免疫沉淀P-gp和PKC。12-肉豆蔻酸酯- 13-乙酸酯是一种二酰基甘油类似物，可诱导PKC向质膜易位，从而增强了这两种蛋白之间的联系。通过直接磷酸化反应测定，抗p -gp免疫沉淀物含有PKC活性。PKC与P-gp的相互作用表现出同工酶特异性：PKC- α、- β、- γ、-epsilon和-phi与P-gp共免疫沉淀，但不与-delta、-mu、-zeta、-lambda共免疫沉淀。这些研究表明，P-gp与PKC密切相互作用并作为底物，该激酶的特异性同工酶可能参与了多药转运体的磷酸化。
Indirect evidence has suggested that P-glycoprotein (P-gp), the multidrug transporter, is phosphorylated by protein kinase C (PKC) and that phosphorylation modulates its transport function. To address the first premise more directly, ie., that P-gp is phosphorylated by PKC, we investigated the interaction between P-gp and PKC in sensitive and multidrug resistant MCF-7 and KB human carcinoma cell lines. We found that P-gp and PKC were coimmunoprecipitated from the multidrug-resistant cell lines MCF-7/AdrR and KB-V-1, using antibodies to either protein. The association between the two proteins was enhanced by phorbol 12-myristate 13-acetate, an analogue of diacylglycerol that induces translocation of PKC to the plasma membrane. The anti-P-gp immunoprecipitates contained PKC activity as measured by direct phosphorylation reactions. The interaction of PKC with P-gp displayed isozyme specificity: PKC-alpha, -beta, gamma, -epsilon, and -phi, but not -delta, -mu, -zeta, -lambda, were found to coimmunoprecipitate with P-gp. These studies indicate that P-gp closely interacts with PKC and serves as a substrate, and that specific isozymes of this kinase may be involved in the phosphorylation of the multidrug transporter.