Speck N A, Baltimore D
Mol Cell Biol. 1987 Mar;7(3):1101-10. doi: 10.1128/mcb.7.3.1101-1110.1987.
Binding sites for six distinct nuclear factors on the 75-base-pair repeat of the Moloney murine leukemia virus enhancer have been identified by an electrophoretic mobility shift assay combined with methylation interference. Three of these factors, found in WEHI 231 nuclear extracts, which we have named LVa, LVb, and LVc (for leukemia virus factors a, b, and c) have not been previously identified. Nuclear factors that bind to the conserved simian virus 40 corelike motif, the NF-1 motif, and the glucocorticoid response element were also detected. Testing of multiple cell lines showed that most factors appeared ubiquitous, except that the NF-1 binding factor was found neither in nuclear extracts from MEL cells nor in the embryonal carcinoma cell lines PCC4 and F9, and core-binding factor was relatively depleted from MEL and F9 nuclear extracts.
通过电泳迁移率变动分析结合甲基化干扰技术，已在莫洛尼鼠白血病病毒增强子的75个碱基对重复序列上鉴定出六个不同核因子的结合位点。在WEHI 231细胞核提取物中发现的其中三个因子，我们将其命名为LVa、LVb和LVc（白血病病毒因子a、b和c），此前尚未被鉴定出来。还检测到了与保守的猿猴病毒40核心样基序、NF-1基序和糖皮质激素反应元件结合的核因子。对多个细胞系的检测表明，大多数因子似乎普遍存在，不过NF-1结合因子在MEL细胞的核提取物以及胚胎癌细胞系PCC4和F9中均未发现，而核心结合因子在MEL和F9核提取物中相对较少。
