The knot structure of DNA "i-motif" is confirmed for the first time in living human cells

DNA is known to have a double helical structure, but it seems to have a knot "i-motifIt is also known that there is a special structure called. It has been reported that i - motif was first found in human living cells.

I-motif DNA structures are formed in the nuclei of human cells | Nature Chemistry
https://www.nature.com/articles/s41557-018-0046-3

New form of DNA discovered inside living human cells | The Independent
https://www.independent.co.uk/news/science/dna-new-discovered-human-cells-living-imotif-australia-research-double-helix-knot-a8318116.html

BREAKING: Scientists have confirmed a new DNA structure inside human cells
https://www.sciencealert.com/scientists-have-confirmed-a-new-dna-structure-inside-living-cells-i-motif-intercalated

Besides double helix structure, DNA has a special structure such as "i-motif" and "G-quadruplexes (guanine quadruplex)". In general DNA, the bases adenine (A) and thymine (T) combine with cytosine (C) and guanine (G) to form a double helix, whereas the four-stranded "DNA" In i-motif which is analogous to "knot", it is said that Cs combine to create a special structure.


This time, we have successfully observed the DNA with the special structure "i-motif" in the living human cells by the research group of Dr. Daniel · Christ of the Garvan Institute of Medical Research. Until now, i-motif structure could only be observed under artificially created conditions in the laboratory, but this is the first time that it was observed in natural human cells.

To identify i-motif in human cells, researchers created small probes using "Y-type" molecules that have the property of imaging with specific substances. The probe is a special one that binds only to i-motif and does not bind to other forms of DNA. Examination of three different types of human cells using a probe to which a fluorescent dye was added confirmed the disappearance of green spots and confirmed the formation and remodeling of i-motif.


I do not know exactly about the function of DNA with a special structure like i-motif. However, some scientists speculate that i-motif is involved in the process of reading DNA sequences and the process of transforming DNA into useful substances. The discovery of i-motif in human cells is expected to enhance the understanding of the mechanism of DNA affecting health and disease.