Endoplasmatic reticulum shaping by generic mechanisms and protein-induced spontaneous curvature

Endoplasmatic reticulum membranes can form extended networks of interconnected tubules (shown on the top) similar to micro-emulsions (shown at the bottom). We describe the physical basis of the formation and stabilization of these extended membrane system by ER-shaping proteins of the reticulon super-family and a generic mechanism maximizing the area-to-volume ratio in the crowded intracellular space.