Tetraspanins at a glance.

Tetraspanins are a family of proteins with four transmembrane domains that play a role in many aspects of cell biology and physiology; they are also used by several pathogens for infection and regulate cancer progression. Many tetraspanins associate specifically and directly with a limited number of proteins, and also with other tetraspanins, thereby generating a hierarchical network of interactions. Through these interactions, tetraspanins are believed to have a role in cell and membrane compartmentalization. In this Cell Science at a Glance article and the accompanying poster, we describe the basic principles underlying tetraspanin-based assemblies and highlight examples of how tetraspanins regulate the trafficking and function of their partner proteins that are required for the normal development and function of several organs, including, in humans, the eye, the kidney and the immune system.