Nucleolar protein PinX1p regulates telomerase by sequestering its protein catalytic subunit in an inactive complex lacking telomerase RNA
Nucleolar protein PinX1p regulates telomerase by sequestering its protein catalytic subunit in an inactive complex lacking telomerase RNA
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DOI：
10.1101/gad.1171804
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发表时间：
2004-02-15
影响因子：
10.5
通讯作者：
Blackburn, EH
中科院分区：
文献类型：
--
作者：
Lin, J;Blackburn, EH
人TRF 1结合蛋白PinX 1抑制端粒酶活性在这里，我们报告酵母PinX 1 p（yPinX 1 p）的过度表达导致端粒缩短和体外端粒酶活性降低。即使在缺乏端粒酶RNA TLC 1或端粒酶相关蛋白Est 1 p和Est 3 p的细胞中，yPinX 1 p也与酵母端粒酶蛋白Est 2 p共免疫沉淀。与yPinX 1 p或TLC 1结合所需的Est 2 p区域相似。此外，我们发现存在两种不同的Est 2 p复合物，含有yPinX 1 p或TLC 1。当TLC 1缺失时，Est 2 p-yPinX 1 p复合物的水平增加，当TLC 1过表达时，Est 2 p-yPinX 1 p复合物的水平降低。因此，我们提出yPinX 1 p通过将其蛋白催化亚基隔离在缺乏端粒酶RNA的无活性复合物中来调节端粒酶。
Human TRF1-binding protein PinX1 inhibits telomerase activity. Here we report that overexpression of yeast PinX1p (yPinX1p) results in shortened telomeres and decreased in vitro telomerase activity. yPinX1p coimmunoprecipitated with yeast telomerase protein Est2p even in cells lacking the telomerase RNA TLC1, or the telomerase-associated proteins Est1p and Est3p. Est2p regions required for binding to yPinX1p or TLC1 were similar. Furthermore, we found two distinct Est2p complexes exist, containing either yPinX1p or TLC1. Levels of Est2p-yPinX1p complex increased when TLC1 was deleted and decreased when TLC1 was overexpressed. Hence, we propose that yPinX1p regulates telomerase by sequestering its protein catalytic subunit in an inactive complex lacking telomerase RNA.