Title of the talk: DNA repair, Droplet Formation and Chaos in Cells
When some human cells are damaged or stressed they respond by oscillating protein densities as have been observed for two famous proteins/transcription factors p53 and NF-kB [1]. The oscillations have a period of 3-5 hours and appear in both healthy and sick cells. p53 is a cancer gene while NF-kB plays a role in diabetes. For p53 we show that that droplets of repair proteins form around damage sites in an oscillating fashion thus preventing Oswald ripening. The period of oscillations provides an optimal time scale for the repair mechanism [2]. By apply an external periodic protein signal, the internal oscillation can lock to the external signal and thus controls the genes. The locking occurs when the ratio between the two frequencies is a rational number leading to Arnold tongues. If tongues overlap, chaotic dynamics appear which strongly influence gene production. Our findings are in good agreement with experimental data from our collaborative groups at Harvard Medical, Beijing and Taiwan.
[1] M.L. Heltberg, S. Krishna, L.P. Kadanoff and M.H. Jensen, "A tale of two rhythms: Locked clocks and chaos in biology (Review)", Cell Systems, 12, 291-303 (2021).
[2] M.S. Heltberg, A. Lucchetti1, F.-S. Hsieh, D.P.M. Nguyen, S.-h.Chen and Mogens H. Jensen, "Enhanced DNA repair through droplet formation and p53 oscillations", Cell 185, 4394–4408 (2022).
Short bio: I did my PhD in Copenhagen under supervision of Per Bak. Then I was a post doc a University of Chicago working with Leo Kadanoff for some years. After working as Ast. Prof. at Nordita for seven years I was employed by The Niels Bohr Institute being a full professor in 1997. Have studied chaotic phenomena, fractals, turbulence and complexity in general. Around ten years ago I turned my attention to applying complex theories in biological systems. In particular I have worked on protein oscillations in cells described dynamical system theory. And the last years studied DNA repair in terms in liquid-liquid phase transitions. I have been secretary general and later President for nive years of the Royal Danish Academy of Science and Letters. Was knighted by Queen Margrethe II in 2017 and knighted to first degree in 2020.
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