Yanagisawa J, Takahashi M, Kanki H, Yano-Yanagisawa H, Tazunoki T, Sawa E, Nishitoba T, Kamishohara M, Kobayashi E, Kataoka S, Sato T
Division of Molecular Oncology, Department of Otolaryngology/Head & Neck Surgery and Pathology, College of Physicians & Surgeons, Columbia University, New York, New York 10032, USA.
J Biol Chem. 1997 Mar 28;272(13):8539-45. doi: 10.1074/jbc.272.13.8539.
Fas (APO-1/CD95), which is a member of the tumor necrosis factor receptor superfamily, is a cell surface receptor that induces apoptosis. A protein tyrosine phosphatase, Fas-associated phosphatase-1 (FAP-1), that was previously identified as a Fas binding protein interacts with the C-terminal 15 amino acids of the regulatory domain of the Fas receptor. To identify the minimal region of the Fas C-terminal necessary for binding to FAP-1, we employed an in vitro inhibition assay of Fas/FAP-1 binding using a series of synthetic peptides as well as a screen of random peptide libraries by the yeast two-hybrid system. The results showed that the C-terminal three amino acids (SLV) of human Fas were necessary and sufficient for its interaction with the third PDZ (GLGF) domain of FAP-1. Furthermore, the direct cytoplasmic microinjection of this tripeptide (Ac-SLV) resulted in the induction of Fas-mediated apoptosis in a colon cancer cell line that expresses both Fas and FAP-1. Since t(S/T)X(V/L/I) motifs in the C termini of several other receptors have been shown to interact with PDZ domain in signal transducing molecules, this may represent a general motif for protein-protein interactions with important biological functions.
Fas（APO-1/CD95）是肿瘤坏死因子受体超家族的成员，是一种诱导细胞凋亡的细胞表面受体。一种蛋白酪氨酸磷酸酶，即Fas相关磷酸酶-1（FAP-1），先前被鉴定为Fas结合蛋白，它与Fas受体调节域的C末端15个氨基酸相互作用。为了确定Fas C末端与FAP-1结合所需的最小区域，我们使用一系列合成肽进行了Fas/FAP-1结合的体外抑制试验，并通过酵母双杂交系统筛选了随机肽库。结果表明，人Fas的C末端三个氨基酸（SLV）对于其与FAP-1的第三个PDZ（GLGF）结构域的相互作用是必需且足够的。此外，将该三肽（Ac-SLV）直接胞质显微注射到同时表达Fas和FAP-1的结肠癌细胞系中，可诱导Fas介导的细胞凋亡。由于其他几种受体C末端的t（S/T）X（V/L/I）基序已被证明可与信号转导分子中的PDZ结构域相互作用，这可能代表了具有重要生物学功能的蛋白质-蛋白质相互作用的一般基序。
