Targa F R, Huesca M, Scherrer K
Institut Jacques Monod, Université de Paris VII, France.
Biochem Biophys Res Commun. 1992 Oct 15;188(1):416-23. doi: 10.1016/0006-291x(92)92401-i.
A silencer element has been identified previously on the 3'-side of the chicken alpha-globin genes placed next to the major enhancer in this domain (Recillas Targa et al., unpublished). Deletion fragments of this negative element show the requirement of the entire DNA segment for maximum silencing activity. Additionally, the sub-fragments including the previously defined SF1 (Silencer Factor 1) sequence seem to play an important role on the negative action of this silencer. Preliminary characterization of the nuclear factor interacting with the SF1 sequence was carried out. Methylation interference experiments show the contact points and, by electrophoretic retardation analysis with SF1 and SF1-mutated oligonucleotides, the critical role of these contacts points on the formation of the DNA-protein complex could be demonstrated. These results provide a basis for further experiments on the characterization and understanding of the mechanisms of action of the coupled positive and negative regulatory elements.
先前已在鸡α-珠蛋白基因3'端鉴定出一个沉默子元件，该基因位于此区域的主要增强子旁边（雷西拉斯·塔尔加等人，未发表）。该负性元件的缺失片段表明，整个DNA片段对最大沉默活性是必需的。此外，包括先前定义的SF1（沉默子因子1）序列的亚片段似乎在该沉默子的负性作用中起重要作用。对与SF1序列相互作用的核因子进行了初步表征。甲基化干扰实验显示了接触点，并且通过用SF1和SF1突变的寡核苷酸进行电泳迁移率分析，可以证明这些接触点在DNA-蛋白质复合物形成中的关键作用。这些结果为进一步研究偶联的正负调控元件的作用机制的表征和理解提供了基础。
