Ehrlich R, Maguire J E, Singer D S
Immunology Branch, National Cancer Institute, Bethesda, Maryland 20892.
Mol Cell Biol. 1988 Feb;8(2):695-703. doi: 10.1128/mcb.8.2.695-703.1988.
Regulatory DNA sequence elements were functionally identified in the 5'-flanking region of a gene, PD1, which encodes a porcine classical transplantation antigen. Both a positive regulatory element and a novel negative regulatory DNA element were mapped within 1.1 kilobases upstream of exon 1. The negative regulatory element reduced the activity of both the homologous PD1 promoter and a heterologous simian virus 40 promoter. In vivo competition experiments indicated that the functions of the PD1 positive and negative regulatory elements are mediated by distinct cellular trans-acting factors. The PD1 positive regulatory element interacted with cellular factors in common with those binding to the simian virus 40 enhancer. Finally, the negative regulatory element required the presence of a positive regulatory element to function. This interaction between positive and negative regulatory elements represents a novel mechanism for regulating gene expression.
在编码猪经典移植抗原的基因PD1的5'侧翼区域中，功能性地鉴定出了调控DNA序列元件。在第1外显子上游1.1千碱基范围内定位到了一个正调控元件和一个新型负调控DNA元件。该负调控元件降低了同源PD1启动子和异源猿猴病毒40启动子的活性。体内竞争实验表明，PD1正调控元件和负调控元件的功能是由不同的细胞反式作用因子介导的。PD1正调控元件与那些结合到猿猴病毒40增强子的细胞因子相互作用。最后，负调控元件需要正调控元件的存在才能发挥作用。正调控元件与负调控元件之间的这种相互作用代表了一种调控基因表达的新机制。
