The International Symposium on Membrane-Less Organelles in Cell Life and Disease will be focused on the characterization of cellular organelles lacking membrane boundaries, as well as on their involvement in cell metabolism and disease progression. It will be held in Seville (Spain), on 7 - 8 March 2023, under the auspices of Ramón Areces Foundation at cicCartuja, a joint research center of the University of Seville (US), the Spanish Research Council (CSIC) and the Autonomous Government of Andalusia.

How do cells enable internal spatiotemporal control of complex biochemical reactions? They have partly solved this question by creating compartments, or organelles, that allow distinct chemical environments. Most of these compartments are surrounded by membranes (nucleus, mitochondria, chloroplasts, lisosomes, etc.). It is thus easy to understand how such membrane-bound compartments cohabit and work in the cells. On the contrary, many other compartments (nucleoli, centrosomes, Cajal bodies, stress granules, etc.) lack membranes and explaining their coexistence inside the cells is harder. Such membrane-less organelles (MLOs) remain separated in the cell by avoiding the mixture of their components with the surroundings. The following questions soon arise: Are there molecules transported in and out of MLOs? How fast must the diffusion of the components within MLOs be to guarantee efficient chemical reactions?

Recent experimental evidences have shown that many MLOs are liquid droplets formed by phase separation, thereby allowing MLO components to be rapidly concentrated in a concrete place in the cell. The transient assembly of liquid drops is driven by i) multivalent weak interactions between signaling domains repetitively included in proteins and RNA, and ii) substantial conformational heterogeneities of intrinsically disordered regions. Under cell pathology and devastating aggregation diseases, liquid-liquid demixing can eventually turn into metastable condensates of intracellular matter, such as glass/hydrogels or amyloid-like fibers, that undergo liquid-solid phase transitions.

Altogether, liquid-liquid phase separation provides a simple but smart mechanism for the cell to control the spatial localization and processing of molecules, without relying on membrane boundaries.

Cellular biology approaches combined with quantitative biophysical and structural tools are required to elucidate how such non-equilibrium events in living cells control intracellular phase behavior. In this Symposium, the confluence between physicists and cellular and molecular biologists will let us go deeply into the formation of MLOs by liquid-liquid phase transitions and the formation of drops (or droplets) inside the cell. This Symposium aims at gathering pioneering scientists in such a cutting-edge interdisciplinary topic to discuss on MLOs and their impact on diseases. Because of its relevance and novelty, the Symposium will host a round table with senior editors of the three top journals influencing science policy (Cell, Nature, Science).

The Symposium is open to the academic community and research centers. No registration fee is required. 

Assistance will be recognized with 0.5 ECTS credits.