Attending #BPS2025? Want to know more about tangible steps you can take to challenge the attacks on science in the U.S.? Please attend an Emergency Town Hall Meeting on Tuesday at 1:30! @biophysicalsoc.bsky.social @blackinbiophys.bsky.social Please spread the word!
High resolution in fixed cells, but temporal events - transient, sub diffraction clusters in live mammalian cells. -ve feedback - 4-5 polymerase load, clusters are released. Cells can hold clusters longer to increase transcriptional events. Dual colour super resolution. TcPALM. Measure active burst, estimate RNAs and correlate with cluster lifetime. Enhancer, mediator, PolII - Mediator and PolII in stem cells. Short lived 11 s. Subset large clusters 300-400 nm in size, long lived 10s of minutes. Lattice lightsheet. 3d, time lapse, 10s of minutes, a full nucleus every 15s or so. Some clusters fuse to merge content. In vivo condensates with liquid like properties. Condensate proximity to Sox2 promoter correlates to mRNA burst intensity. Du et al, Cell, 2024. Higher burst size, higher frequency of burst events. 1.5-2 fold higher proximal to a PolII condensate. Anticorrelation between distance and burst size. When condensate contacts enhancer and generates. If superenhancer is distal from condensate, then no burst. Mediator/PolII, Superenhancer DNA, nascent mRNA in 3 colours. Movie of condensate moving in to contact the superenhancer, Gene promoter active and mRNA increases. Is the condensate/superenhancer contact active? Yes, cohesion required to loop DNA - precise architecture of the DNA to achieve a burst. Cohesion loops DNA and stops at an enhancer element upstream of the promoter. Lee et al 2024, Condensates - complex, liquid droplets? Proximity mini turbo ID? Accumulate any cargo of interest to be concentrated in the condensate. Turn on blue light and generate condensate localisation? Light induced targeting of endogenous condensates. Cargo-miniturbo-ID-GFP blue light on, accumulates in condensate, biotinylation accumulating. LiTEC with BioID for proteomics on condensates. Some missing... Chimeric mining. Pass droplets through mass spec - often ignore low intensity peaks. Looked for background peaks. More to follow up..
Session 10 Ibrahim Cissé-Super-res imaging of transcription. Cooperativity in weak & transient biological interactions. PolII clustering in a cell nucleus w STORM. Limitations for weak and transient interactions. Lightsheet microscopy to follow polymerase condensates & gene bursts #LorneProteins2025
Our inspirational Leach Lecturer Frances Separovic. A champion of women in STEM. "A reluctant chemist". Croatia to Broken Hill. A peace lover. First in family to finish primary school. And one cool Professor 😎. #LorneProteins2025
It was a great pleasure to attend #LorneProteins2025. It was a wonderful meeting with top-notch science and a super-friendly vibe. It was great to escape freezing NYC and spend a few days on the beach. All should come next year!
🦠A team led by the Lippincott-Schwartz Lab used a new technique developed at Janelia called high-resolution template matching, or HRTM, to uncover in unprecedented detail the movement of ribosomes – the molecular structures that synthesize proteins inside cells.
🔗 hhmi.news/401LKMq
Before you disappear into the holiday break 🎄 , mark your calendars for a the next #WWSC talk:
"More excited by other proteins than voltage: the unconventional function of the sodium leak channel complex" by @plesslab.bsky.social January 21st 2025.
www.sodiumchannelseminars.org for info and link.
season finale. imagine a future without the empire.
#RussianColonialism
open.substack.com/pub/maksymer...
