Epimorphin

A multifunctional membrane protein with dual topology. Its C terminus is membrane anchored. When the N terminus is on the cytosolic face it acts as a t-SNARE involved in intracellular vesicle docking and is called Syntaxin-2. When flipped inside out, i.e. N terminus hangs out on the extracellular surface (by some nonclassical secretion pathway) it acts as a versatile morphogen and is called epimorphin. This membrane protein enjoys the double choice of another form of topological alternatives of being targeted to either apical or basolateral surface of an epithelial cell in a regulated way depending on various contexts. When expressed by mesenchymal cells it can instruct epithelial morphogenesis at epithelial mesenchymal interfaces.