Light on pits

摘要

Writing last month in Cell, Ehrlich and colleagues reported progress in a 40-year line of investigation. They have studied the 'coated pits' that form on the surface of cells and which take up material from the surface and the extracellular environment. Seminal work by Roth and Porter first showed that there are regions on the surface of mosquito eggs that are specialized to allow these cells to take up yolk proteins from their environment. Roth and Porter called these areas coated pits because the surface facing the inside of the cell was coated with an electron-dense material. That material was later shown to be made up of a protein named clathrin. Over the past 20 years, many other components of coated pits have been identified. These include the AP2 adaptor protein, which links transmembrane cargo molecules to the clathrin lattice, and dynamin, an enzyme required to transform coated pits into small, spherical vesicles inside the cell (although its precise role remains controversial).