Dimitar Sasselov
Harvard University, MA·Chemistry
Ultraviolet (UV) sunlight can damage DNA and RNA, the molecules that carry genetic information. The damage creates structural defects that cause mutations or even kill cells.
- Fields
Chemistry
Biophysics
Astronomy & Astrophysics
- Topics
RNA damage
RNA self-repair
UV photochemistry
- Grants
- 1 known grant, through Jun 2028
What they work on
- Elucidate the mechanism by which short RNA strands repair UV-induced damage by transferring an electron from a long-lived excited state to the damaged site.
- Test how general RNA self-repair is across sequence length, base choice and non-canonical nucleotides such as inosine, extending beyond two- and four-base strands.
- Determine how sequence direction and stacking between bases such as G and A control repair efficiency, building on the contrast seen in DNA strands GAT=T versus T=TAG.
- Explore UV-induced charge-transfer states in tRNA-like RNA strands and with cofactors such as NADH as possible switches in the early evolution of translation, including RNA aminoacylation and enzyme-free RNA replication.
More about the research
Sunlight can also heal some of this damage. The lab recently discovered that some short RNA strands can repair themselves under UV light, much as DNA can. Under UV light, these strands enter energized states that last long enough to pass an electron to the damaged site and fix it. No enzymes that repair RNA this way are known. That makes the finding relevant to how the earliest life, which had no enzymes, might have survived, and to how modern cells and viruses deal with damaged RNA.
Why it matters
Handling of RNA damage by cells and viruses has drawn new attention since the pandemic. Knowing how RNA can repair itself under sunlight could reveal damage-handling mechanisms quite different from known DNA repair, with possible implications for physiology and medicine. The work could also explain which RNA sequences were favored on the early Earth and how primitive cells survived error-prone RNA copying.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
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Jia Sheng
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Synthesize azobenzene-based photoswitchable nucleosides, which change shape under different wavelengths of light, insert them into RNA strands, and characterize base-pairing stability and structure using X-ray crystallography and computational modeling.
The school
Harvard University: 42 labs on PI Pages, $1.5B a year on research, 712 research doctorates a year.
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