Join us for MLS Seminar featuring Dr. Geraldine Seydoux, Sheldon Professor in Medical Discovery at the Johns Hopkins University School of Medicine Department of Molecular Biology & Genetics! The title of her talk is RNA granules: functional compartments or incidental condensates?
The Seydoux lab studies how single-cell embryos localize RNAs and proteins to pattern developmental potential. We use genetics, microscopy and biochemistry to identify, observe and manipulate RNAs and proteins in and out of cells. Polarization of the cytoplasm and asymmetric cell division are common strategies to pattern cells and embryos. We study the mechanisms that polarize the C. elegans embryo right after fertilization. We have found that localized changes in the rates of protein diffusion drive the formation of protein gradients across the cytoplasm. We want to understand the mechanisms that limit and patter protein diffusion in the cytoplasm. RNA granules are protein/RNA condensates proposed to form by liquid-liquid phase separation, a process akin to the separation of oil and vinegar in salad dressing. Studying the P granules of C. elegans, we have found that RNA granules are stabilized in the cytoplasm by a gel-like coat. The coat is made by intrinsically-disordered proteins that are stimulated by RNA to form gels in vitro. Similar proteins exist across eukarya, raising the possibility that protein gels may be a common strategy to stabilize liquid condensates in eukaryotic cells.
