Abstract
Telomeres are specialized chromatin structures that protect chromosomal ends. Protection of telomeres 1 (Pot1) binds to the telomeric G-rich overhang, thereby protecting telomeres and regulating telomerase. Mammalian POT1 and TPP1 interact and constitute part of the six-protein shelterin complex. Here we report that Tpz1, the TPP1 homolog in fission yeast, forms a complex with Pot1. Tpz1 binds to Ccq1 and the previously undiscovered protein Poz1 (Pot1-associated in Schizosaccharomyces pombe), which protect telomeres redundantly and regulate telomerase in positive and negative manners, respectively. Thus, the Pot1-Tpz1 complex accomplishes its functions by recruiting effector molecules Ccq1 and Poz1. Moreover, Poz1 bridges Pot1-Tpz1 and Taz1-Rap1, thereby connecting the single-stranded and double-stranded telomeric DNA regions. Such molecular architectures are similar to those of mammalian shelterin, indicating that the overall DNA-protein architecture is conserved across evolution.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Carrier Proteins / chemistry
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Carrier Proteins / genetics
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Carrier Proteins / metabolism*
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Chromatin Immunoprecipitation
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DNA, Fungal / metabolism
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DNA-Binding Proteins
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Immunoprecipitation
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Molecular Sequence Data
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Mutation
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Protein Binding
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Protein Structure, Tertiary
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Schizosaccharomyces / genetics
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Schizosaccharomyces / metabolism*
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Schizosaccharomyces pombe Proteins / chemistry
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Schizosaccharomyces pombe Proteins / genetics
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Schizosaccharomyces pombe Proteins / metabolism*
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Shelterin Complex
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Telomerase / metabolism
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Telomere / metabolism
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Telomere / physiology*
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Telomere / ultrastructure
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Telomere-Binding Proteins / chemistry
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Telomere-Binding Proteins / genetics
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Telomere-Binding Proteins / metabolism*
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Two-Hybrid System Techniques
Substances
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Carrier Proteins
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Ccq1 protein, S pombe
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DNA, Fungal
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DNA-Binding Proteins
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Poz1 protein, S pombe
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Rap1 protein, S pombe
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Schizosaccharomyces pombe Proteins
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Shelterin Complex
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Telomere-Binding Proteins
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Tpz1 protein, S pombe
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pot1 protein, S pombe
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Telomerase