HP1γ通过与肝细胞核因子1α相互作用抑制其转录活性  

Heterochromatin protein 1γ interacts with hepatocyte nuclear factor 1α and inhibits its transcription activity

作　　者：李典镕[1] 詹轶群[2] 许望翔[2] 于淼[2] 

机构地区：[1]天津大学,天津300027 [2]军事医学科学院放射与辐射医学研究所,北京100850

出　　处：《军事医学》2012年第7期516-519,共4页Military Medical Sciences

基　　金：国家重大科学研究计划(2006CB910802)

摘　　要：目的初步探讨肝细胞核因子1α(HNF1α)与异染色质蛋白1γ(HP1γ)的相互作用及其功能。方法首先以成人肝cDNA文库为模板,通过聚合酶链反应(PCR)扩增出552 bp的HP1γcDNA片段,然后亚克隆到真核表达载体pcDNA3.1/Myc-HisB,转染HepG2细胞后提取总蛋白进行Western印迹鉴定,进而通过GST沉降实验验证HP1γ与HNF1α的相互作用区段,最后通过荧光素酶报告基因实验HP1γ/HNF1α相互作用的功能。结果通过测序证实真核表达载体Myc-HP1γ构建成功,Western印迹证明Myc-HP1γ可在真核细胞中表达;GST沉降结果表明HP1γ与HNF1α的N端1-189氨基酸相互作用;报告基因实验证明HP1γ抑制HNF1α的转录活性。结论 HP1γ通过与HNF1α相互作用抑制HNF1α的转录活性。Objective To study the protein-protein interaction between hepatocyte nuclear factor 1 α （HNF1α） and heterochromatin protein 1γ（HP1γ） and its function. Methods First, the human full-length HP1γ （ CBX3 ） was amplified by polymerase chain reaction （PCR） from the human liver cDNA and subcloned into the pcDNA3.1/Myc-HisB vector. The protein expression was detected through Western-blot. The function of HP1γ//HNF1 α interaction was studied through luciferase assays. Results The expression construct Myc-HP1γ/was generated successfully and confirmed by DNA sequencing. Western-blot result showed that Myc-HP1γ,/could be expressed in HepG2 cells. In vitro glutathione S-transferase pull-down assays revealed that the HP1γ//HNF1α interaction was mediated through the N terminal aa 1 - 189 of HNF1α. Moreover, luciferase reporter analyses showed that CBX3 inhibited the transcriptional activities of HNF1α in cultured cells. Conclusion These findings raise the intriguing possibility that CBX3 is a new regulator of HNF1α and participates in HNF1α-mediated transcription regulation through protein-protein interaction.

关 键 词：肝细胞核因子1α 异染色质蛋白1γ 蛋白质相互作用 转录调节 

分 类 号：R363[医药卫生—病理学]