Here, there, and everywhere: The importance of ER membrane contact sites

Our textbook image of organelles has changed. Instead of revealing isolated cellular compartments, the picture now emerging shows organelles as largely interdependent structures that can communicate through membrane contact sites (MCSs). MCSs are sites where opposing organelles are tethered but do not fuse. MCSs provide a hybrid location where the tool kits of two different organelles can work together to perform vital cellular functions, such...