A phosphoprotein helps lipid droplets stay in shape

Lipid droplets (LDs) are key lipid storage structures in cells. One might think that they simply result from lipid molecules separating out within the aqueous intracellular environment. However, closer investigation has revealed that LDs are wellorganized organelles surrounded by proteins that tightly control lipid entry into and exit from these organelles. One LD-associated protein is perilipin 1 (PLIN1) (1). It is a highly abundant protein in fat cells (adipocytes) and the first protein identified on the LD surface (Fig. 1), as reported in a JBC paper recognized as a Classic here (2), authored by Andrew Greenberg (Fig. 2), his late mentor Constantine Londos, and colleagues at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health. JBC reached out to Greenberg to learn about the discovery of PLIN1 and how this research milestone has spurred further investigations into fat storage andmetabolism.