Cell cycle localization, dimerization, and binding domain architecture of the telomere protein cPot1.
Cell cycle localization, dimerization, and binding domain architecture of the telomere protein cPot1.
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端粒蛋白 cPot1 的细胞周期定位、二聚化和结合域结构。
DOI：
10.1128/mcb.24.5.2091-2102.2004
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发表时间：
2004
影响因子：
5.3
通讯作者：
Price,CarolynM
中科院分区：
文献类型：
--
作者：
Wei,Chao;Price,CarolynM
Pot1 is a single-stranded-DNA-binding protein that recognizes telomeric G-strand DNA. It is essential for telomere capping in Saccharomyces pombe and regulates telomere length in humans. Human Pot1 also interacts with proteins that bind the duplex region of the telomeric tract. Thus, like Cdc13 from S. cerevisiae, Pot 1 may have multiple roles at the telomere. We show here that endogenous chicken Pot1 (cPot1) is present at telomeres during periods of the cell cycle when t loops are thought to be present. Since cPot1 can bind internal loops and directly adjacent DNA-binding sites, it is likely to fully coat and protect both G-strand overhangs and the displaced G strand of at loop. The minimum binding site of cPot1 is double that of the S. pombe DNA-binding domain. Although cPot can self associate, dimerization is not required for DNA binding and hence does not explain the binding-site duplication. Instead, the DNA-binding domain appears to be extended to contain a second binding motif in addition to the conserved oligonucleotide-oligosaccharide (OB) fold present in other G-strand-binding proteins. This second motif could be another OB fold. Although dimerization is inefficient in vitro, it may be regulated in vivo and could promote association with other telomere proteins and/or telomere compaction.
