Membrane prewetting by condensates promotes tight junction belt formation

Time-resolve proximity proteomics of tight junction. To understand how the tight junction belt is assembled and positioned, we combined APEX2 proximity proteomics of the main junctional scaffold protein ZO-1 with a calcium switch tissue formation assay.This combination allowed us to synchronize the initiation of junction assembly in the entire tissue by the addition of calcium to the culture medium and quantify the time evolution of the junctional proteome during the assembly process using proximity proteomics.