Warfarin causes the degradation of protein C precursor in the endoplasmic reticulum.
Warfarin causes the degradation of protein C precursor in the endoplasmic reticulum.
复制标题
华法林引起内质网中蛋白C前体的降解。
DOI：
10.1021/bi00004a009
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发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
T. Koide
中科院分区：
文献类型：
--
作者：
F. Tokunaga;S. Wakabayashi;T. Koide
华法林是一种维生素K拮抗剂，已知会破坏微粒体维生素K周期，导致血浆中抗凝血因子蛋白C水平降低，以及其他一些依赖维生素K的凝血因子。在这里，我们检测了华法林对人肾293或BHK细胞中表达的重组蛋白C分泌的影响。在瞬时表达中，与维生素k处理的细胞相比，华法林导致蛋白C分泌量减少2-4倍。用稳定细胞进行的脉冲追踪实验表明，尽管重组蛋白C在维生素K存在的情况下分泌，但华法林处理的细胞中放射性总量的减少表明细胞内降解。这种降解取决于华法林的浓度，不受内质网(ER)-高尔基转运抑制剂（brefeldin A）或溶酶体抑制剂（氯喹和NH4Cl）的抑制。因此，在华法林存在下合成的蛋白C可能被选择性地降解，这种降解发生在高尔基体前非溶酶体区室。在所测试的蛋白酶抑制剂中，n -乙酰- leu - leu -methioninal和n -乙酰- leu - leu -norleucinal阻断了在华法林存在下合成的蛋白C前体的降解，并以剂量依赖的方式积聚在细胞内。然而，这两种抑制剂都不会干扰维生素k处理细胞中蛋白C前体的分泌。因此，半胱氨酸蛋白酶(s)似乎是负责的降解。（摘要删节250字）
Warfarin, an antagonist of vitamin K, is known to disrupt the microsomal vitamin K cycle, which results in a decrease in the plasma level of protein C, an anticoagulant factor, as well as some other vitamin K-dependent coagulation factors. Here, we examined the effect of warfarin on the secretion of recombinant protein C expressed in human kidney 293 or BHK cells. In transient expression, warfarin caused a 2-4-fold decrease in the quantity of protein C secreted, compared to findings with vitamin K-treated cells. Pulse-chase experiments using stable cells showed that, although recombinant protein C was secreted in the presence of vitamin K, the decrease in the total amount of radioactivity in the warfarin-treated cells suggested intracellular degradation. This degradation depended on the concentration of warfarin and was not inhibited by an endoplasmic reticulum (ER)-Golgi transport inhibitor (brefeldin A) or by lysosomotropic inhibitors (chloroquine and NH4Cl). Thus, protein C synthesized in the presence of warfarin is probably selectively degraded, and this degradation occurs in a pre-Golgi, nonlysosomal compartment. Among the protease inhibitors tested, N-alpha-acetyl-Leu-Leu-methioninal and N-alpha-acetyl-Leu-Leu-norleucinal blocked the degradation of protein C precursor synthesized in the presence of warfarin, and the precursor accumulated intracellularly, in a dose-dependent manner. Both inhibitors, however, did not disturb the secretion of protein C precursor in the vitamin K-treated cells. Thus, a cysteine protease(s) appeared to be responsible for the degradation.(ABSTRACT TRUNCATED AT 250 WORDS)