IDENTIFICATION AND FUNCTIONAL-CHARACTERIZATION OF A TIA-1-RELATED NUCLEOLYSIN
IDENTIFICATION AND FUNCTIONAL-CHARACTERIZATION OF A TIA-1-RELATED NUCLEOLYSIN
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DOI：
10.1073/pnas.89.18.8681
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发表时间：
1992-09-15
影响因子：
11.1
通讯作者：
ANDERSON, P
中科院分区：
文献类型：
--
作者：
KAWAKAMI, A;TIAN, QS;ANDERSON, P
我们最近报道了一种细胞毒性颗粒相关 RNA 结合蛋白的分子克隆，命名为 TIA-1。重组 TIA-1 在透化细胞中诱导 DNA 断裂的能力表明，该蛋白是负责诱导溶细胞淋巴细胞 (CTL) 靶标细胞凋亡的颗粒成分。在这里，我们报告了编码 TIA-1 相关蛋白（称为 TIAR）的 cDNA 的特征。推导的 TIAR 氨基酸序列表明它是一种 42 kDa 的蛋白质，具有三个 RNA 结合结构域和一个羧基末端辅助结构域。尽管TIA-1和TIAR的RNA结合结构域具有>85%的氨基酸同源性，但它们的羧基末端辅助结构域只有51%同源性。 TIAR 的羧基末端含有溶酶体靶向基序，表明 TIAR 可能是一种细胞毒性颗粒相关蛋白。与 TIA-1 一样，纯化的重组 TIAR 在透化的靶细胞中诱导 DNA 断裂。尽管核后上清液的免疫印迹分析显示 TIA-1 蛋白仅限于 CTL，但 PCR 分析显示 TIA-1 和 TIAR mRNA 转录物在多种细胞类型中表达。我们的数据表明，CTL 颗粒至少含有两种参与 CTL 杀伤的候选溶核素。
We recently reported the molecular cloning of a cytotoxic granule-associated RNA-binding protein designated TIA-1. The ability of recombinant TIA-1 to induce DNA fragmentation in permeabilized cells suggested that this protein is the granule component responsible for inducing apoptosis in cytolytic lymphocyte (CTL) targets. Here we report the characterization of a cDNA encoding a TIA-1-related protein designated TIAR. The deduced amino acid sequence of TIAR reveals it to be a 42-kDa protein possessing three RNA-binding domains and a carboxyl-terminal auxiliary domain. Although the RNA-binding domains of TIA-1 and TIAR share >85% amino acid homology, their carboxyl-terminal auxiliary domains are only 51% homologous. The carboxyl terminus of TIAR contains a lysosome-targeting motif, indicating that TIAR is probably a cytotoxic granule-associated protein. Like TIA-1, purified recombinant TIAR induced DNA fragmentation in permeabilized target cells. Although immunoblotting analysis of post-nuclear supernatants revealed TIA-1 protein to be restricted to CTLs, PCR analysis revealed the expression of TIA-1 and TIAR mRNA transcripts in a wide variety of cell types. Our data suggest that the granules of CTLs contain at least two candidate nucleolysins involved in CTL killing.