Eventos
O venres 31 maio de 2024 a Dra. Karina Pombo García (Rosalind Franklin Institute) ofrecerá o seminario "Wetting of the junctional condensates at the apical interface promotes tight junction formation", dentro do ciclo "CINBIO Seminar Programme".
Será ás 11:00h na Sala de seminarios de Torre CACTI.
ABSTRACT:
Biomolecular condensates enable cell compartmentalization by acting as membrane-less organelles. How cells control the interactions of condensates with other cellular structures such as membranes to drive morphological transitions remains poorly understood. We discovered that formation of a tight junction belt, which is essential for sealing epithelial tissues, is driven by a wetting phenomenon which promotes the growth of a condensed ZO-1 layer around the apical membrane interface. Using temporal proximity proteomics in combination with imaging and thermodynamic theory, we found that the polarity protein PATJ mediates a transition of ZO-1 into a condense surface layer that elongates around the apical interface. In line with the experimental observations, our theory of condensate growth shows that the speed of elongation depends on the binding affinity of ZO-1 to the apical interface and is constant. Using PATJ mutations we show that ZO-1 interface binding is necessary and sufficient for tight junction belt formation. Our results demonstrate how cells exploit the collective biophysical properties of protein condensates at membrane interfaces to shape mesoscale structures.
BIO:
I did my PhD in Chemistry between Monash University Melbourne and TUD & Helmohz in Germany on development of radiopharmaceuticals and nanomaterials for molecular imaging. Later, I shifted to do a postdoc in cell biology and biophysics at the Max Planck for Molecular Cell biology and Genetics in Dresden . During my postdoc, I made a key discovery on understanding the process by which epithelial cells connect via wetting of liquid-condensates of tight junctions, working together with Prof. Honigmann, Hyman & Jülicher Labs. Exciting times during the postdoc also allow me to work on lipid imaging, stress granules, small drugs on nuclear condensates, all using super-resolution STED microscopy. I have just opened my lab at the Rosalind Franklin Institute & affiliated to the University of Oxford where we will explore the molecular organization of cell adhesions during tissue assembly & their damage in intestinal diseases.
