Development of protein-based inhibitors of the proprotein of convertase SKI-1/S1P - Processing of SREBP-2, ATF6, and a viral glycoprotein
Development of protein-based inhibitors of the proprotein of convertase SKI-1/S1P - Processing of SREBP-2, ATF6, and a viral glycoprotein
复制标题
DOI：
10.1074/jbc.m313764200
复制
发表时间：
2004-04-23
影响因子：
4.8
通讯作者：
Seidah, NG
中科院分区：
文献类型：
--
作者：
Pullikotil, P;Vincent, M;Seidah, NG
膜结合转录因子（例如甾醇调节元件结合蛋白 (SREBP) 和 ER 应激反应因子 ATF6）以及某些出血热病毒的糖蛋白的加工是由前蛋白转化酶 SKI-1/S1P 启动的。迄今为止，尚无已知的疏水性氨基酸特异性 SKI-1 的基于细胞蛋白的抑制剂。碱性氨基酸特异性转化酶（例如弗林蛋白酶和 PC5）或 α(1)-PDX（α(1)-抗胰蛋白酶 (α(1)-AT) 的变体）的前片段在反应位点环上表现出 RIPR358 序列，被证明可以有效抑制这些分泌蛋白酶。因此，我们测试了 SKI-1-(1-198) 或 alpha(1)-AT 的 198 个氨基酸前段的各种点突变体的 SKI-1 抑制潜力。瞬时转染数据表明，在研究的众多突变体中，R134E 前片段突变体或 α(1)-AT 反应位点环变体 RRVL358、RRYL358 和 RRIL358 是 SKI-1 的最佳特异性细胞抑制剂。观察到的内源 SREBP-2、外源 ATF6 和 PDGF-A (RRLL86) 变体的加工抑制>55%，在稳定转染子中达到相似的 80%。我们还表明，SKI-1 与这些 alpha(1)-AT 变体形成 SDS 稳定复合物，但不与野生型 alpha(1)-AT 或 alpha(1)-PDX 形成。最后，这些抑制剂还被证明会影响克里米亚-刚果出血热病毒糖蛋白的加工和稳定性。
Processing of membrane-bound transcription factors such as sterol regulatory element-binding proteins (SREBPs) and the ER-stress response factor ATF6, and glycoproteins of some hemorrhagic fever viruses are initiated by the proprotein convertase SKI-1/S1P. So far, no cellular protein-based inhibitor of the hydrophobic-amino acid specific SKI-1 is known. The prosegment of the basic-amino acid specific convertases (e.g. furin and PC5) or alpha(1)-PDX, a variant of alpha(1)-antitrypsin (alpha(1)-AT) exhibiting an RIPR358 sequence at the reactive site loop, were shown to potently inhibit these secretory proteinases. Accordingly, we tested the SKI-1-inhibitory potential of various point mutants of either the 198 amino acid preprosegment of SKI-1-(1-198) or alpha(1)-AT. Transient transfections data showed that, out of numerous mutants studied, the R134E prosegment mutant or the alpha(1)-AT reactive site loop variants RRVL358, RRYL358 and RRIL358 are the best specific cellular inhibitors of SKI-1. The observed inhibition of the processing of endogenous SREBP-2, exogenous ATF6 and a PDGF-A (RRLL86) variant were >55% and reach similar to80% in stable transfectants. We also show that SKI-1 forms SDS-stable complexes with these alpha(1)-AT variants, but not with wild-type alpha(1)-AT or alpha(1)-PDX. Finally, these inhibitors were also shown to affect the processing and stability of the Crimean-Congo hemorrhagic fever virus glycoprotein.