Purpose of review: Cytosolic lipid droplets are now recognized as dynamic organelles. This review summarizes our current understanding of the mechanisms involved in the formation of lipid droplets, the importance of lipid droplet-associated proteins and the link between lipid droplet accumulation and development of insulin resistance.
Recent findings: Lipid droplets are formed as primordial droplets and they increase in size by fusion. This fusion process requires the alpha-soluble N-ethylmaleimide-sensitive factor adaptor protein receptor SNAP23, which is also involved in the insulin-dependent translocation of a glucose transporter to the plasma membrane. Recent data suggest that SNAP23 is the link between increased lipid droplet accumulation and development of insulin resistance. Lipid droplets also form tight interactions with other organelles. Furthermore, additional lipid droplet-associated proteins have been identified and shown to play a role in droplet assembly and turnover, and in sorting and trafficking events.
Summary: Recent studies have identified a number of key proteins that are involved in the formation and turnover of lipid droplets, and SNAP23 has been identified as a link between accumulation of lipid droplets and development of insulin resistance. Further understanding of lipid droplet biology could indicate potential therapeutic targets to prevent accumulation of lipid droplets and associated complications.