Zhong Z, Shiue L, Kaplan S, de Lange T
Rockefeller University, New York, New York 10021.
Mol Cell Biol. 1992 Nov;12(11):4834-43. doi: 10.1128/mcb.12.11.4834-4843.1992.
We have identified a DNA-binding activity with specificity for the TTAGGG repeat arrays found at mammalian telomeres. This factor, called TTAGGG repeat factor (TRF), is present in nuclear extracts of human, mouse, and monkey cells. TRF from HeLa cells was characterized in detail by electrophoretic mobility shift assays. It binds double-stranded TTAGGG repeats in linear and circular DNAs. Single-stranded repeats are not recognized. The optimal site for TRF appears to contain more than six contiguous TTAGGG repeats. Tandem arrays of TAGGG, TTTAGGG, TTTTAGGG, TTGGGG, and TTAGGC repeats do not bind TRF well, indicating that TRF preferentially recognizes the telomeric repeat sequence present at mammalian chromosome ends. The apparent molecular mass of this factor, based on recovery of TRF from sodium dodecyl sulfate-polyacrylamide gels, is approximately 50 kDa. We suggest that TRF binds along the length of mammalian telomeres.
我们已经鉴定出一种对哺乳动物端粒处的TTAGGG重复序列具有特异性的DNA结合活性。这种因子被称为TTAGGG重复因子（TRF），存在于人、小鼠和猴细胞的核提取物中。通过电泳迁移率变动分析对来自HeLa细胞的TRF进行了详细表征。它能结合线性和环状DNA中的双链TTAGGG重复序列。单链重复序列不被识别。TRF的最佳结合位点似乎包含六个以上连续的TTAGGG重复序列。TAGGG、TTTAGGG、TTTTAGGG、TTGGGG和TTAGGC重复序列的串联阵列与TRF结合不佳，这表明TRF优先识别存在于哺乳动物染色体末端的端粒重复序列。基于从十二烷基硫酸钠-聚丙烯酰胺凝胶中回收的TRF，该因子的表观分子量约为50 kDa。我们认为TRF沿着哺乳动物端粒的长度结合。
