[The Svedberg & Spotlight] Genome Maintenance at Higher Resolution
June 1, 2026 @ 15:15 – 16:15 CEST
Prof. Taekjip Ha
Harvard Medical School & Boston Children’s Hospital
Dates:
June 1 at 15:15 (The Svedberg seminar)
Venue: BMC, C8:301, Uppsala
June 2 at 15:15 (Spotlight seminar)
Venue: Air&Fire, Tomtebodavägen 23 A, Solna
Abstract:
My research program focuses on the theme of genome maintenance at higher resolution. Genome maintenance, because the accurate duplication and repair of our genome is critical for a healthy life and for informing potential therapies for genetic diseases. Higher resolution, because improved resolution in space and time—encompassing single-molecule, single-cell, and single-base-pair resolution—allows us to ask and answer questions inaccessible to traditional tools
I will first discuss our discovery of homology search mechanisms in mammalian cells, enabled by our very fast CRISPR technology that uses light to activate DNA cleavage by Cas9 with a time resolution of seconds, several hundred-fold better than previous approaches. Here, we found that a DNA motor protein called cohesin grabs and scans the RAD51 filament against the sister chromosome in search of a homologous sequence, explaining how cells recover from a DNA break accurately and rapidly.
In the second part of the lecture, I will present our MINFLUX nanoscopy studies of DNA replication machinery, in particular the MCM complexes that act as replicative helicases. We visualize individual MCM complexes in cells and directly detect the double hexameric MCM (DH). During S phase, a subset of DHs separates up to ~85 nm, generating single MCM hexamers. Furthermore, cohesin is dispensable for MCM loading but required to maintain replisome coupling during S phase. Together, these findings establish cohesin as a versatile genomic architect, actively driving chromatin scanning to preserve genome stability while orchestrating the precise spatiotemporal organization of the active replisome.
Biography:
Dr. Taekjip Ha is George D. Yancopoulos Professor of Pediatrics in honor Frederick W. Alt at Harvard Medical School and director and senior investigator of Program in Cellular and Molecular Medicine at Boston Children’s Hospital. He has been an investigator with the Howard Hughes Medical Institute since 2005. He received a bachelor’s in physics from Seoul National University in 1990 and Physics PhD from University of California at Berkeley in 1996. After postdoctoral training at Stanford, he was a Physics professor at University of Illinois at Urbana-Champaign (2000-2015), where he co-directed an NSF Physics Frontier Center, and Bloomberg Distinguished Professor at Johns Hopkins University (2015-2023). He is a member of the National Academy of Science and the National Academy of Medicine, and a fellow of the American Academy of Arts and Sciences. He received Ho-Am Prize in Science (2011), Kazuhito Kinosita Award in single molecule biophysics (2018) and Barany Award for young investigators (2007). He was named Searle Scholar (2001) and Sloan Fellow (2003). He has served on Editorial Boards for Science (2011-present), Cell (2009-2020) and eLife (2014-2020). He co-chaired the National Academies committee on Toward Sequencing and Mapping of RNA Modifications (2022-2024). He served as President of the Biophysical Society (2023-2024).
Webpage : https://www.tjhalab.com/
Hosts:
Sebastian Deindl, UU
Hans Bloom, KTH
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