Mechanistic studies for the role of cellular nucleic-acid-binding protein (CNBP) in regulation of c-myc transcription
Mechanistic studies for the role of cellular nucleic-acid-binding protein (CNBP) in regulation of c-myc transcription
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细胞核酸结合蛋白（CNBP）在c-myc转录调节中的作用机制研究
DOI：
10.1016/j.bbagen.2013.06.007
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发表时间：
2013-10-01
影响因子：
3
通讯作者：
Li, Ding
中科院分区：
文献类型：
--
作者：
Chen, Siqi;Su, Lijuan;Li, Ding
背景：已知 c-myc 核酸酶超敏元件 (NHE) III1 富含鸟嘌呤的序列折叠成 G-四链体，随后充当转录沉默子。细胞核酸结合蛋白（CNBP）是一种高度保守的锌指蛋白，具有多种生物学功能，可以与c-myc NHE III1区结合，特别是单链富含G的序列。方法：本研究采用了多种方法，包括蛋白质的克隆、表达和纯化、EMSA、CD、FRET、Ch-IP、RNA干扰、荧光素酶报告基因测定、SPR、免疫共沉淀和共转染，结果：我们发现人CNBP在体外和细胞内特异性结合c-myc NHE III1区富含G的序列，随后促进G-四链体的形成。 CNBP 可诱导体内 c-myc 转录短暂减少，随后增加。 CNBP与NM23-H2的相互作用导致了c-myc转录的增加。结论：基于上述实验结果，提出了一种涉及G-四链体相关CNBP/NM23-H2相互作用的c-myc转录调节新机制。一般意义：这些发现表明，通过NHE III1区域对c-myc转录的调节可能是由涉及复杂的蛋白质-蛋白质相互作用的机制控制的，并提出了CNBP作为潜在的新的可能性。基于 CNBP 在 c-myc 转录中的生物学功能的抗癌靶点。 (c) 2013 Elsevier B.V. 保留所有权利。
Background: Guanine-rich sequence of c-myc nuclease hypersensitive element (NHE) III1 is known to fold in G-quadruplex and subsequently serves as a transcriptional silencer. Cellular nucleic-acid-binding protein (CNBP), a highly conserved zinc-finger protein with multiple biological functions, could bind to c-myc NHE III1 region, specifically to the single strand G-rich sequence.Methods: In the present study, a variety of methods, including cloning, expression and purification of protein, EMSA, CD, FRET, Ch-IP, RNA interference, luciferase reporter assay, SPR, co-immunoprecipitation, and co-transfection, were applied to investigate the mechanism for the role of CNBP in regulating c-myc transcription.Results: We found that human CNBP specifically bound to the G-rich sequence of c-myc NHE III1 region both in vitro and in cellulo, and subsequently promoted the formation of G-quadruplex. CNBP could induce a transient decrease followed by an increase in c-myc transcription in vivo. The interaction of CNBP with NM23-H2 was responsible for the increase of c-myc transcription.Conclusions: Based on above experimental results, a new mechanism, involving G-quadruplex related CNBP/NM23-H2 interaction, for the regulation of c-myc transcription was proposed.General significance: These findings indicated that the regulation of c-myc transcription through NHE III1 region might be governed by mechanisms involving complex protein-protein interactions, and suggested a new possibility of CNBP as a potential anti-cancer target based on CNBP's biological function in c-myc transcription. (c) 2013 Elsevier B.V. All rights reserved.