Correction of defective protein kinesis of human P-glycoprotein mutants by substrates and modulators
Correction of defective protein kinesis of human P-glycoprotein mutants by substrates and modulators
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DOI：
10.1074/jbc.272.2.709
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发表时间：
1997-01-10
影响因子：
4.8
通讯作者：
Clarke, DM
中科院分区：
文献类型：
--
作者：
Loo, TW;Clarke, DM
越来越多的证据表明异常的蛋白质折叠或运输（蛋白质动力学）导致疾病。我们已经使用P-糖蛋白作为模型蛋白来开发克服蛋白质动力学缺陷的策略。人P-糖蛋白的错误加工突变体作为核心糖基化生物合成中间体保留在内质网中并迅速降解。然而，在药物底物或调节剂如辣椒素、环孢菌素、长春碱或维拉帕米的存在下合成突变蛋白，导致在细胞表面出现完全糖基化和功能性蛋白。这些效应具有剂量依赖性，并在添加底物后数小时内发生。促进错误折叠突变体加工的能力似乎与所用的细胞系和突变位置无关。在这些底物的存在下，将跨膜区段、细胞外或细胞质环、核苷酸结合结构域或接头区中具有突变的P-糖蛋白加工成完全成熟的形式。这些药物底物或调节剂作为P-糖蛋白的特异性化学伴侣，因为它们对囊性纤维化跨膜传导调节因子的Delta F508突变体无效。因此，防止蛋白质错误折叠的一种可能策略是在蛋白质的特定底物或调节剂存在下进行合成。
There is growing evidence that abnormal protein folding or trafficking (protein kinesis) leads to diseases, We have used P-glycoprotein as a model protein to develop strategies to overcome defects in protein kinesis. Mis-processed mutants of the human P-glycoprotein are retained in the endoplasmic reticulum as core glycosylated biosynthetic intermediates and rapidly degraded. Synthesis of the mutant proteins in the presence of drug substrates or modulators such as capsaicin, cyclosporin, vinblastine, or verapamil, however, resulted in the appearance of a fully glycosylated and functional protein at the cell surface. These effects were dose-dependent and occurred within a few hours after the addition of substrate. The ability to facilitate processing of the misfolded mutants appeared to be independent of the cell lines used and location of the mutation. P-glycoproteins with mutations in transmembrane segments, extracellular or cytoplasmic loops, the nucleotide-binding domains, or the linker region were processed to the fully mature form in the presence of these substrates. These drug substrates or modulators acted as specific chemical chaperones for P-glycoprotein because they were ineffective on the Delta F508 mutant of cystic fibrosis transmembrane conductance regulator. Therefore, one possible strategy to prevent protein misfolding is to carry out synthesis in the presence of specific substrates or modulators of the protein.