December 15, 2011

Instead of fat-shaming our fat cells, we need to thank them for providing our bodies with essential energy. Lipid droplets play an important role in storing this fat and are quite dynamic. Today’s image is from a paper describing the dynamics that allow lipid droplets to grow.

Lipid droplets (LDs) are dynamic lipid storage organelles that participate in a variety of cellular processes. Lipid droplet misregulation has been linked to diseases such as diabetes and obesity. A recent paper sheds light on how LDs grow, and describes how an LD-associated protein called Fsp27 contributes to LD growth. Gong and colleagues found that Fsp27 is enriched at the points where two lipid droplets contact each other. Lipids are exchanged between the two LDs at these contact points, with a net lipid transfer from smaller to larger LDs that eventually results in the merging of the LDs. Images above are of adipocytes, which are specialized cells that store fat for energy, showing Fsp27 (red in all images) localization on lipid droplets (green in top row). The points where two LDs contact each other has an enrichment of Fsp27 (arrowheads). Other LD-associated proteins (green in middle, bottom rows), however, are not enriched at LD contact sites.

Gong, J., Sun, Z., Wu, L., Xu, W., Schieber, N., Xu, D., Shui, G., Yang, H., Parton, R., & Li, P. (2011). Fsp27 promotes lipid droplet growth by lipid exchange and transfer at lipid droplet contact sites originally published in The Journal of Cell Biology, 195 (6), 953-963 DOI: 10.1083/jcb.201104142