Pharmacological knock-down of the presenilin 1 heterodimer by a novel γ-secretase inhibitor -: Implications for presenilin biology
Pharmacological knock-down of the presenilin 1 heterodimer by a novel γ-secretase inhibitor -: Implications for presenilin biology
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DOI：
10.1074/jbc.m103075200
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发表时间：
2001-11-30
影响因子：
4.8
通讯作者：
Shearman, MS
中科院分区：
文献类型：
--
作者：
Beher, D;Wrigley, JDJ;Shearman, MS
β-淀粉样前体蛋白被γ-分泌酶膜内切割是产生淀粉样β肽的最终加工事件，淀粉样β肽被认为是阿尔茨海默病的病原体。早老素基因中的错义突变与早发性阿尔茨海默病共分离，并且，最近，早老素和γ-分泌酶的身份之间的密切的生物化学联系已经建立。在这里，我们首次描述了某些有效的γ-分泌酶抑制剂能够干扰早老素1（PS1）的内蛋白水解过程。此外，我们鉴定了一种新的γ-分泌酶抑制剂，{1 S-苄基-4R-[1-（5-环己基-2-氧代-2，3-二氢-1H-苯并[e][1，4]二氮杂卓-3（R，S）-基氨基甲酰基）-S-乙基氨基甲酰基]-2R-羟基-5-苯基-戊基}-氨基甲酸叔丁酯（CBAP），其不仅与PS1物理相互作用，而且在长期治疗后产生PS1片段的“药理学敲低”。这表明所观察到的全长PS1的积累是由其内蛋白水解的直接抑制引起的。随后使用CBAP作为生物学工具，在不存在外源PS1表达的情况下增加全长PS1水平，这提供了野生型PS1内蛋白水解对于PS1/γ-分泌酶复合物组装或运输都不是必需的证据。此外，在基于细胞的系统中，CBAP不完全概括PS1功能丧失表型。即使β-淀粉样前体蛋白裂解和Notch受体的S3裂解被CBAP抑制，也未观察到Trk受体成熟受损。
Intramembranous cleavage of the beta -amyloid precursor protein by gamma -secretase is the final processing event generating amyloid-beta peptides, which are thought to be causative agents for Alzheimer's disease. Missense mutations in the presenilin genes co-segregate with early-onset Alzheimer's disease, and, recently, a close biochemical linkage between presenilins and the identity of gamma -secretase has been established. Here we describe for the first time that certain potent gamma -secretase inhibitors are able to interfere with the endoproteolytic processing of presenilin 1 (PS1). In addition, we identified a novel gamma -secretase inhibitor, {1S-benzyl-4R-[1-(5-cyclohexyl-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3(R,S)-ylcarbamoyl)-S-ethylcarbamoyl]-2R-hydroxy-5-phenyl-pentyl}-carbamic acid tertbutyl ester (CBAP), which not only physically interacts with PS1, but upon chronic treatment produces a "pharmacological knock-down" of PS1 fragments. This indicates that the observed accumulation of full-length PS1 is caused by a direct inhibition of its endoproteolysis. The subsequent use of CBAP as a biological tool to increase full-length PS1 levels in the absence of exogenous PS1 expression has provided evidence that wild-type PS1 endoproteolysis is not required either for PS1/gamma -secretase complex assembly or trafficking. Furthermore, in cell-based systems CBAP does not completely recapitulate PS1 loss-of-function phenotypes. Even though the beta -amyloid precursor protein cleavage and the S3 cleavage of the Notch receptor are inhibited by CBAP, an impairment of Trk receptor maturation was not observed.