Emerging methodologies to investigate lipid-protein interactions

Cellular membranes are composed of hundreds of different lipids, ion channels, receptors and scaffolding complexes that act as signalling and trafficking platforms for processes fundamental to life. Cellular signalling and membrane trafficking are often regulated by peripheral proteins, which reversibly interact with lipid molecules in highly regulated spatial and temporal fashions. In most cases, one or more modular lipid-binding domain(s) mediate recruitment of peripheral proteins to specific cellular membranes. These domains, of which more than 10 have been identified since 1989, harbour structurally selective lipid-binding sites. Traditional in vitro and in vivo studies have elucidated how these domains coordinate their cognate lipids and thus how the parent proteins associate with membranes. Cellular activities of peripheral proteins and subsequent physiological processes depend upon lipid binding affinities and selectivity. Thus, the development of novel sensitive and quantitative tools is essential in furthering our understanding of the function and regulation of these proteins. As this field expands into new areas such as computational biology, cellular lipid mapping, single molecule imaging, and lipidomics, there is an urgent need to integrate technologies to detail the molecular architecture and mechanisms of lipid signalling. This review surveys emerging cellular and in vitro approaches for studying protein-lipid interactions and provides perspective on how integration of methodologies directs the future development of the field.