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“Intracellular Aggregates and Condensates” – December 16
| Event Date | December 16, 2024 |
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| Time | 8:45 am - 9:45 pm - EST |
| Tags | |
| Website | https://plan.core-apps.com/ascbembo2024/event/d4d661d4c37405b7b49858236dc11127 |
| Organizers | ASCB|EMBO |
| Venue | San Diego Convention Center, San Diego CA |
| Location | 111 W Harbor Drive San Diego, CA 92101 United States + Google Map |
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Cell Bio 2024 – An ASCB|EMBO Meeting
SY5 – Super-resolution imaging of transcription in living cells
Author Block: I. Cisse; Max Planck Institute of Immunobiology and Epigenetics, Freiburg, GERMANY.
We will discuss the latest efforts in our laboratory to develop highly sensitive methods of microscopy, to go directly inside living cells and uncover the behavior of single biomolecules as they effect their function in transcription. Transcription is the first step in gene expression regulation, during which genetic information on DNA is decoded into RNA transcripts. Methodologically, the so-called live cell single molecule and super-resolution techniques – that break the optical diffraction limit – are revealing with unprecedented spatial and temporal resolutions, novel emergent phenomena inside the living cells. We will discuss our recent discoveries on highly dynamic biomolecular clustering, and phase transitions in vivo. These discoveries are challenging the ‘textbook view’ on how our genome (DNA) is decoded in living cells.
SY6 – Translational Activation By A Ribonucleoprotein Condensate
Author Block: R. Lehmann; Department of Biology, Whitehead Institute and MIT, Cambridge, MA.
Biomolecular condensates compartmentalize the intracellular environment in space and time. Condensates can promote efficiency, achieve specificity, and allow the regulation of biochemical processes within the cell including transcription, RNA regulation, and cell signaling. Ribonucleoprotein (RNP) granules are a type of condensate that serve as hubs of post-transcriptional regulation by concentrating specific RNAs and RNA binding proteins (RBPs). RNP granules, like stress granules, processing bodies, and neuronal transport granules, are known to assemble and store translationally repressed mRNA. Whether RNP granules can also activate translation remains unclear. This motivated us to study the molecular processes by which RNP granules may achieve localized protein synthesis. Germ granules, the embryonic, germ cell-determining RNP granules in Drosophila, are sites of active translation. By imaging translation at the single-molecule level using the SunTag method, we observe that translation of germ granule enriched mRNAs such as nanos, preferentially occurs on the germ granule surface with the 3’UTR embedded internally. Translation in germ granules depends on the concentrated activity of Oskar, an RNA-binding protein that serves as a scaffold for granule phase separation, and the DEAD-box protein Vasa/Ddx4. Smaug, a repressor of translation, antagonizes germ granule activation. Compartmentalized relief from translational repression is achieved through the sequestration of the Smaug repressor into germ granules by the disordered linker region of Oskar. The Drosophila germ granule reveals a technically amendable model for studying localized translational activation, its subcellular compartmental organization, and dynamic regulation in a developing organism.