HnRNP A3 binds to and protects mammalian telomeric repeats in vitro
HnRNP A3 binds to and protects mammalian telomeric repeats in vitro
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DOI：
10.1016/j.bbrc.2007.04.177
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发表时间：
2007-06-29
影响因子：
3.1
通讯作者：
Nakagama, Hitoshi
中科院分区：
文献类型：
--
作者：
Tanaka, Etsuko;Fukuda, Hirokazu;Nakagama, Hitoshi
hnRNP家族蛋白的生物学功能是广泛多样的，并且涉及前mRNA加工、转录调节、重组和端粒维持。在研究小卫星DNA生物学功能的过程中，我们从NIH 3 T3细胞中分离了几种与小鼠小卫星Pc-1结合的核蛋白，该蛋白由d（GGCAG）重复序列串联阵列组成。MNBP-A是一种小卫星结合蛋白，它与Pc-1重复序列的富含G的单链结合，被证明与hnRNP A3相同。重组hnRNP A3被证明与单链端粒d（TTAGGG）重复的结合亲和力比d（GGCAG）重复高得多。hnRNPA 3与单链端粒重复序列的结合保护了端粒重复序列免受核酸酶的攻击，并抑制了端粒酶反应和DNA合成。这些结果表明hnRNPA 3在稳定维持端粒重复序列中可能具有生物学作用。(C)2007年由Elsevier Inc.出版
The biological function of hnRNP family proteins is widely diverse and involved in pre-mRNA processing, transcriptional regulation, recombination, and telomere maintenance. In the course of our study on the elucidation of biological functions of minisatellite DNA, we isolated several nuclear proteins that bind to the mouse minisatellite Pc-1, which consists of a tandem array of d(GGCAG) repeats, from NIH3T3 cells. One of the minisatellite binding proteins, MNBP-A, which binds to a single-stranded G-rich strand of the Pc-1 repeat, was proven identical to the hnRNP A3. Recombinant hnRNP A3 was demonstrated to bind to the single-stranded telomeric d(TTAGGG) repeat with much higher affinity than the d(GGCAG) repeat. Binding of hnRNP A3 to the single-stranded telomeric repeat protected the repeat from nuclease attack, and inhibited both telomerase reaction and DNA synthesis in vitro. These results suggest a possible biological role of hnRNP A3 in the stable maintenance of telomere repeats. (C) 2007 Published by Elsevier Inc.