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Quadruplex formation is necessary for stable PNA invasion into duplex DNA of BCL2 promoter region

Guanine-rich sequences are highly abundant in the human genome, especially in regulatory regions. Because guanine-rich sequences have the unique ability to form G-quadruplexes, these structures may play a role in the regulation of gene transcription. In previous studies, we demonstrated that formati...

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Detalles Bibliográficos
Autores principales: Onyshchenko, Mykola I., Gaynutdinov, Timur I., Englund, Ethan A., Appella, Daniel H., Neumann, Ronald D., Panyutin, Igor G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3167611/
https://www.ncbi.nlm.nih.gov/pubmed/21593130
http://dx.doi.org/10.1093/nar/gkr259
Descripción
Sumario:Guanine-rich sequences are highly abundant in the human genome, especially in regulatory regions. Because guanine-rich sequences have the unique ability to form G-quadruplexes, these structures may play a role in the regulation of gene transcription. In previous studies, we demonstrated that formation of G-quadruplexes could be induced with peptide nucleic acids (PNAs). PNAs designed to bind the C-rich strand upstream of the human BCL2 gene promoted quadruplex formation in the complementary G-rich strand. However, the question whether G-quadruplex formation was essential for PNA invasion remained unanswered. In this study, we compared PNA invasion in the native and mutant, i.e. not forming G-quadruplex, BCL2 sequences and showed that G-quadruplex is required for effective PNA invasion into duplex DNA. This finding provides strong evidence for not only sequence-specific, but also quadruplex specific, gene targeting with PNA probes. In addition, we examined DNA-duplex invasion potential of PNAs of various charges. Using the gel shift assay, chemical probing and dimethyl sulfate (DMS) protection studies, we determined that uncharged zwitterionic PNA has the highest binding specificity while preserving efficient duplex invasion.