Cargo Nets

Like intestines in our bodies, cells have a network of pipes and tubes through which stuff is continuously passing, and from which small sausage-like entities can pinch off. These sausage-like vesicles carry molecules between factory-like compartments and to the cell’s surface. The oily skin, or membrane, and proteins surrounding the vesicles are important for maintaining their shape. Until recently little was known about the coat proteins because it is difficult to examine their structure. Pictured is a 3D computer model of a flash-frozen vesicle from a series of snapshots taken with a scanning electron microscope. False colours make the structures clearer and show for the first time the coat proteins (green, red and blue) form a net around the membrane (yellow). The model suggests the formation of coat proteins can adapt to cargoes of different sizes.

Written by Julie Webb

Julie Webb

Writer

Julie began her career as a researcher in genetics. In 2000 she won a Wellcome Trust award for her work on a collaborative science drama, staged at the Edinburgh Festival. She now works as a freelance science writer and communicator.

• John Briggs, European Molecular Biology Laboratory, Germany
• Felix Wieland, Heidelberg University, Germany
• Reprinted with permission from AAAS.
• Published in Science 336:1451 (2012)