Zbtb34 is a novel zinc finger protein, which is revealed by biological software analysis to have 3 zinc fingers, but its functions remain unknown. In this study, mouse Zbtb34 cDNA was amplified by PCR and inserted into the plasmid pEGFP-N1 to generate Zbtb34-EGFP fusion protein. The upregulation of Zbtb34 in mouse embryonic stem cells promoted telomere elongation and increased cell proliferation. In order to understand the above phenomena, the telomere co-immunoprecipitation technique was employed to investigate the relationship between Zbtb34 and telomeres. The results indicated that Zbtb34 could bind to the DNA sequences of the telomeres. Alanine substitution of the third zinc finger abolished such binding. Since Pot1 is the only protein binding to the single-stranded DNA at the end of the telomeres, we further investigated the relationship between Zbtb34 and Pot1. The results revealed that the upregulation of Zbtb34 decreased the binding of Pot1b to the telomeres. Through the upregulation of Pot1b, the binding of Zbtb34 to the telomeres was also reduced. In conclusion, we showed that the main biological function of Zbtb34 was to bind telomere DNA via its third ZnF, competing with Pot1b for the binding sites, resulting in telomere elongation and cell proliferation.

中文翻译：

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Zbtb34通过延长端粒长度促进胚胎干细胞增殖

Zbtb34是一种新型锌指蛋白，生物软件分析显示其具有3个锌指，但其功能仍不清楚。本研究通过PCR扩增小鼠Zbtb34 cDNA，并将其插入质粒pEGFP-N1中，生成Zbtb34-EGFP融合蛋白。小鼠胚胎干细胞中 Zbtb34 的上调促进端粒伸长并增加细胞增殖。为了了解上述现象，采用端粒免疫共沉淀技术研究Zbtb34与端粒之间的关系。结果表明Zbtb34可以结合端粒的DNA序列。第三个锌指的丙氨酸取代消除了这种结合。由于Pot1是唯一与端粒末端单链DNA结合的蛋白，我们进一步研究了Zbtb34和Pot1之间的关系。结果表明，Zbtb34 的上调降低了 Pot1b 与端粒的结合。通过 Pot1b 的上调，Zbtb34 与端粒的结合也减少。总之，我们表明Zbtb34的主要生物学功能是通过其第三个ZnF结合端粒DNA，与Pot1b竞争结合位点，导致端粒伸长和细胞增殖。