Vaults and telomerase share a common subunit, TEP1
Vaults and telomerase share a common subunit, TEP1
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DOI：
10.1074/jbc.274.46.32712
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发表时间：
1999-11-12
影响因子：
4.8
通讯作者：
Rome, LH
中科院分区：
文献类型：
--
作者：
Kickhoefer, VA;Stephen, AG;Rome, LH
穹窿是功能不确定的大的胞质核糖核蛋白复合物。哺乳动物的穹窿有两种高分子量蛋白质，分别为193和240 kDa。我们已经确定了部分cDNA编码的240 kDa的穹窿蛋白，并确定它是相同的哺乳动物端粒酶相关的组件，TEP1。TEP1是四膜虫：p80端粒酶蛋白的哺乳动物同源物，并且已经显示与哺乳动物端粒酶RNA和催化蛋白亚基hTERT特异性相互作用。我们发现，虽然TEP1是拱顶颗粒的一个组成部分，拱顶没有检测到端粒酶活性。使用酵母三杂交试验，我们证明了几个人的vRNA相互作用的序列特异性的方式与TEP1。TEP1蛋白的羧基末端存在16个WD 40重复序列，这对于该蛋白在穹窿（一种具有八重对称性的颗粒）中发挥结构或组织作用是一个方便的数字。TEP1蛋白在穹窿和端粒酶之间的共享表明TEP1可能在核糖核蛋白结构、功能或组装的某些方面发挥共同作用。
Vaults are large cytoplasmic ribonucleoprotein complexes of undetermined function. Mammalian vaults have two high molecular mass proteins of 193 and 240 kDa. We have identified a partial cDNA encoding the 240-kDa vault protein and determined it is identical to the mammalian telomerase-associated component, TEP1. TEP1 is the mammalian homolog of the Tetrahymena: p80 telomerase protein and has been shown to interact specifically with mammalian telomerase RNA and the catalytic protein subunit hTERT. We show that while TEP1 is a component of the vault particle, vaults have no detectable telomerase activity. Using a yeast three-hybrid assay we demonstrate that several of the human vRNAs interact in a sequence-specific manner with TEP1. The presence of 16 WD40 repeats in the carboxyl terminus of the TEP1 protein is a convenient number for this protein to serve a structural or organizing role in the vault, a particle with eight-fold symmetry. The sharing of the TEP1 protein between vaults and telomerase suggests that TEP1 may play a common role in some aspect of ribonucleoprotein structure, function, or assembly.