On the road to unraveling the molecular functions of ether lipids.

Ether lipids are glycerolipids further classified into alkyl-ether and alkenyl-ether (also termed plasmalogens) lipids. The two ether lipid subclasses share the first steps of their synthesis. However, alkyl-ether and alkenyl-ether lipids differ in their structure and physico-chemical properties (featuring different head groups) and, thus, probably in their functions. Ether lipids have intermittent distribution across the evolutionary tree and defects in their synthesis have been shown to perturb cellular homeostasis and lead to disease in humans. Here, we review their structure, their interactions with other lipids, and their potential roles in cellular functions, such as membrane homeostasis and membrane trafficking. Moreover, we discuss still unclear aspects of these lipids such as their subcellular distribution, and the need to unravel their molecular functions as well as how novel tools to study lipid biology will help clarify these aspects.