Fouquet C, DuBow M S
Department of Microbiology & Immunology, McGill University, Montreal, Quebec, Canada.
Biochem Int. 1992 Jul;27(3):457-64.
Highly-repetitive satellite DNA's are generally located in centromeric heterochromatin, yet little is known about how they are maintained and condensed. In an effort to address this question, we have searched for specific satellite DNA-binding proteins in cell-free extracts (both total cellular and nuclear), prepared from HeLa cells, using southwestern blotting. Four polypeptides were detected that specifically bound to a human 1797 bp EcoRI satellite II DNA, which consists in large part of tandemly repeated pentamer (5' TTCCA 3') units, but not to a control probe from plasmid pBR322. These proteins have apparent molecular weights of 100, 93, 77 and 34 kDa and were termed satellite binding protein (Sbp) -1, -2, -3, and -4, respectively.
高度重复的卫星DNA通常位于着丝粒异染色质中，但对于它们如何维持和浓缩却知之甚少。为了解决这个问题，我们使用蛋白质印迹法在从HeLa细胞制备的无细胞提取物（全细胞和细胞核提取物）中寻找特定的卫星DNA结合蛋白。检测到四种多肽，它们特异性地结合到一个1797 bp的人类EcoRI卫星II DNA上，该DNA大部分由串联重复的五聚体（5'TTCCA 3'）单元组成，但不与质粒pBR322的对照探针结合。这些蛋白质的表观分子量分别为100、93、77和34 kDa，分别被称为卫星结合蛋白（Sbp）-1、-2、-3和-4。
