Heregulin, a new interactor of the telosome/shelterin complex in human telomeres.
Heregulin, a new interactor of the telosome/shelterin complex in human telomeres.
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TREE -GULIN是人类端粒中塞体/庇护所建筑群的新互动者。
DOI：
10.18632/oncotarget.4962
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发表时间：
2015-11-24
期刊：
影响因子：
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通讯作者：
Lupu R
中科院分区：
文献类型：
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作者：
Menendez JA;Benboudjema L;Vellon L;Rubio MA;Espinoza I;Campisi J;Lupu R
端粒的长度、形状和功能取决于六个核心端粒相关蛋白的复合物，称为端粒或shelterin复合物。我们在这里证明，heregulin家族的生长因子（HRGβ2）的异构体β2是一个新的相互作用的端粒/shelterin复合物在人类端粒。使用高通量酵母双杂交（Y2 H）筛选分析蛋白质-蛋白质相互作用，鉴定出RAP 1（从酵母到哺乳动物唯一保守的端粒蛋白）作为HRGβ2的新型相互作用伴侣。RAP 1的缺失分析显示，先前被认为募集端粒长度负调节因子的连接域与HRGβ2特异性相互作用。免疫共沉淀和成像实验表明，除了RAP 1，HRGβ2可以与RAP 1相关的端粒重复序列结合因子2（TRF 2）。HRGβ2的缺失分析证实，核定位信号（nuclear localization signal，NLS）是HRGβ2负调控端粒长度所必需的，而HRGβ2的N端（胞外）氨基酸足以与RAP 1/TRF 2相互作用，促进端粒缩短。综上所述，我们的研究确定核HRGβ2是一种以前未知的调节因子，预计可由RAP 1连接结构域招募，以负调节人类细胞中的端粒长度。我们目前的研究结果表明，一个新的，但可能不是最后一个，意想不到的访客已经到达了“端粒/庇护所镇”。
Telomere length, shape and function depend on a complex of six core telomere-associated proteins referred to as the telosome or shelterin complex. We here demonstrate that the isoform β2 of the heregulin family of growth factors (HRGβ2) is a novel interactor of the telosome/shelterin complex in human telomeres. Analysis of protein-protein interactions using a high-throughput yeast two-hybrid (Y2H) screen identified RAP1, the only telomere protein that is conserved from yeasts to mammals, as a novel interacting partner of HRGβ2. Deletion analysis of RAP1 revealed that the linker domain, a region previously suggested to recruit negative regulators of telomere length, interacts specifically with HRGβ2. Co-immunoprecipitation and imaging experiments demonstrated that, in addition to RAP1, HRGβ2 could associate with the RAP1-associated telomeric repeat binding factor 2 (TRF2). Deletion analysis of HRGβ2 confirmed that a putative nuclear localization signal (NLS) was necessary for nuclear HRGβ2 to exert a negative regulation of telomere length whereas the N-terminus (extracellular) amino acids of HRGβ2 were sufficient to interact with RAP1/TRF2 and promote telomere shortening. Taken together, our studies identify nuclear HRGβ2 as one of the previously unknown regulators predicted to be recruited by the RAP1 linker domain to negatively regulate telomere length in human cells. Our current findings reveal that a new, but likely not the last, unexpected visitor has arrived to the “telosome/shelterin town”.