Hairpin structures formed by alpha satellite DNA of human centromeres are cleaved by human topoisomerase IIalpha

Although centromere function has been conserved through evolution, apparently no interspecies consensus DNA sequence exists. Instead, centromere DNA may be interconnected through the formation of certain DNA structures creating topological binding sites for centromeric proteins. DNA topoisomerase II...

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Bibliographic Details
Published in:Nucleic acids research 2008-11, Vol.36 (19), p.6165-6174
Main Authors: Jonstrup, Anette Thyssen, Thomsen, Tina, Wang, Yong, Knudsen, Birgitta R, Koch, Jørn, Andersen, Anni H
Format: Article
Language:English
Subjects:
Antigens, Neoplasm - metabolism
Base Sequence
Centromere - chemistry
DNA Topoisomerases, Type II - metabolism
DNA, Satellite - chemistry
DNA, Satellite - metabolism
DNA-Binding Proteins - antagonists & inhibitors
DNA-Binding Proteins - metabolism
Enzyme Inhibitors - pharmacology
Humans
Models, Biological
Molecular Sequence Data
Nucleic Acid Conformation
Teniposide - pharmacology
Topoisomerase II Inhibitors
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Summary:Although centromere function has been conserved through evolution, apparently no interspecies consensus DNA sequence exists. Instead, centromere DNA may be interconnected through the formation of certain DNA structures creating topological binding sites for centromeric proteins. DNA topoisomerase II is a protein, which is located at centromeres, and enzymatic topoisomerase II activity correlates with centromere activity in human cells. It is therefore possible that topoisomerase II recognizes and interacts with the alpha satellite DNA of human centromeres through an interaction with potential DNA structures formed solely at active centromeres. In the present study, human topoisomerase IIalpha-mediated cleavage at centromeric DNA sequences was examined in vitro. The investigation has revealed that the enzyme recognizes and cleaves a specific hairpin structure formed by alpha satellite DNA. The topoisomerase introduces a single-stranded break at the hairpin loop in a reaction, where DNA ligation is partly uncoupled from the cleavage reaction. A mutational analysis has revealed, which features of the hairpin are required for topoisomerease IIalpha-mediated cleavage. Based on this a model is discussed, where topoisomerase II interacts with two hairpins as a mediator of centromere cohesion.
ISSN:1362-4962
DOI:10.1093/nar/gkn640