Congratulations to Harvey and Hugo on their new preprint on how DNA loop extrusion may mediate DNA double-strand break repair! Here's the abstract:
DNA double-strand breaks (DSBs) occur every cell cycle and must be efficiently repaired. Non-homologous end joining (NHEJ) is the dominant pathway for DSB repair in G1-phase. The first step of NHEJ is to bring the two DSB ends back into proximity (synapsis). However, although synapsis is generally assumed to occur through passive diffusion, we show here that passive diffusion is unlikely to be consistent with the speed and efficiency of NHEJ observed in cells. Instead, we hypothesize that DNA loop extrusion facilitates synapsis. By combining experimentally constrained simulations and theory, we show that the simplest loop extrusion model only modestly facilitates synapsis. Instead, a loop extrusion model with targeted loading of loop extruding factors (LEFs), a small portion of long-lived LEFs as well as LEF stabilization by boundary elements and DSB ends achieves fast synapsis with near 100% efficiency. We propose that loop extrusion plays an underappreciated role in DSB repair.
Check out BioRxiv for the full article!
The Hansen headed to Sacco's Bowl Haven / American Flatbread last week to try our hand at candlepin bowling (surprisingly difficult) and flatbread pizza (unsurprisingly delicious). Though most of our balls ended in the gutter, creativity was at an all-time high and the trick shots were especially entertaining. Shoutout to Hugo for getting the lone strike of the evening and to Italy for inventing pizza.
Last week we all gathered in the bioinstrumentation lab to get some hands-on experience building microscopes. After two hours of excellently-delivered, high-quality teaching content from Domenic, two coffee trips, one lunch trip, and a birthday celebration, we built a two-color epifluorescence microscope. It was a lot of work, but in the end we were able to image our own cells, and we were even able to see our tagged loci. Watch out Zeiss!
This August we took a small break from our cutting edge research at the bench to celebrate the summer with axe throwing! Everyone put up their best fight, but ultimately Sarah was crowned the Axe Throwing Champion. The lab is now fully equipped and prepared for whatever the Fall semester throws at us.
See the full story at MIT News: https://news.mit.edu/2021/scene-mit-stroke-lightning-beauty-nature-architecture-0709
New preprint: Enhancer-promoter interactions and transcription are maintained upon acute loss of CTCF, Cohesin, WAPL, and YY1
Our recent award from The Alexander and Margaret Stewart Trust and the Pew Foundation was featured in MIT news news.mit.edu/2021/anders-sejr-hansen-awarded-pew-stewart-grant-cancer-research-0630
This award will help fund Shdema's project on understanding the regulation of c-MYC in normal cells and its dysregulation cancer.