Diffusion-driven self-assembly of emerin nanodomains at the nuclear envelope

Abstract: Emerin, a nuclear membrane protein with important biological roles in mechanotransduction and nuclear shape adaptation, self-assembles into nanometer-size domains at the inner nuclear membrane. The size and emerin occupancy of these nanodomains change with applied mechanical stress as well as under emerin mutations associated with Emery-Dreifuss muscular dystrophy (EDMD). Through a combination of theory and experiment we show here that a simple reaction-diffusion model explains the self-assembly of emerin nanodomains. Our model yields quantitative agreement with experimental observations on the size and occupancy of emerin nanodomains for wild-type emerin and EDMD-associated mutations of emerin, with and without applied forces, and allows successful prediction of emerin diffusion coefficients from observations on the overall properties of emerin nanodomains. Our results provide a physical understanding of EDMD-associated defects in emerin organization in terms of changes in key reaction and diffusion properties of emerin and its nuclear binding partners.