Small-molecule-based Human Genome G4 Profiling Reveals Potential Gene Regulation Activity. Homo sapiens

G-quadruplexes (G4s) are a type of secondary structure of nucleic acids, the formation of which depends on the ¦Ð-¦Ð stacking of guanine-rich sequences. Herein, we present a readily accessible strategy, based on small molecule pulldown, for direct genomic G4 profiling of HEK 293T cells. A small molecule was rationally designed, containing PDP on one end and biotin on the other, joined by a 24-unit-long hydrophilic PEG linker. G4s isolation from genomic DNA annealed in potassium chloride buffer beforehand, has identified a total of 51446 PQS, which mainly distribute in introns and intergenic regions. Incubating cells with PDP for 3 h to 72 h resulted in the differential expression of a variety of genes, indicating a potential function of G4s in gene regulation.