Bilaud T, Brun C, Ancelin K, Koering C E, Laroche T, Gilson E
Laboratoire de Biologie Moléculaire et Cellulaire, UMR49, Centre National de la Recherche Scientifique, Ecole Normale Supérieure de Lyon, France.
Nat Genet. 1997 Oct;17(2):236-9. doi: 10.1038/ng1097-236.
Natural chromosomal ends are stabilized by proteins that bind duplex telomeric DNA repeats. In human cells, the TTAGGG Repeat Factor 1 (TRF1) was identified by two independent studies, one screening for factors that bind duplex telomeric DNA and the other screening for proteins containing a particular Myb motif called the telobox, which is required for telomeric repeat recognition (Fig. 1a; refs 3-5). A second human open reading frame, orf2, contains a telobox sequence and encodes a polypeptide that specifically recognizes mammalian telomeric repeat DNA in vitro. We show that two proteins of 65 and 69 kD, expressed in HeLa cells, contain the orf2 telobox sequence. These proteins are collectively termed TRF2. Affinity-purified antibodies specific for anti-TRF2 label the telomeres of intact human chromosomes, strengthening the correlation between occurrence of telobox and telomere-repeat recognition in vivo.
天然染色体末端由与双链端粒DNA重复序列结合的蛋白质稳定。在人类细胞中，两个独立的研究鉴定出了端粒重复序列结合因子1（TRF1），一项研究筛选与双链端粒DNA结合的因子，另一项研究筛选含有特定Myb基序（称为端粒盒）的蛋白质，端粒重复序列识别需要该基序（图1a；参考文献3 - 5）。第二个人类开放阅读框orf2含有端粒盒序列，并编码一种在体外能特异性识别哺乳动物端粒重复DNA的多肽。我们发现，在HeLa细胞中表达的两种65kD和69kD的蛋白质含有orf2端粒盒序列。这些蛋白质统称为TRF2。抗TRF2特异性亲和纯化抗体标记完整人类染色体的端粒，加强了端粒盒的存在与体内端粒重复序列识别之间的相关性。
