Lipids that are not immediately being used for energy production are stored inside lipid droplets, in fat cells, also called adipocytes. A recent study by researchers from the University of Helsinki and University of Texas Southwestern has looked into mechanisms of lipid droplet formation.
The main finding of the research is a new protein structure and an understanding of its functional significance. The protein named seipin is known to be important in the formation of lipid droplets. The study published in Science in November 2025 revealed that the adipose tissue-specific microprotein adipogenin forms a complex with seipin and stabilizes its structure. This, in turn, alters the function of seipin, leading to the formation of fewer but larger lipid droplets within the cell.
The article is a collaboration between the groups of Professor Elina Ikonen and Professor Ilpo Vattulainen at the University of Helsinki and the team led by Professor Philipp Scherer at the University of Texas Southwestern.
Typically, white adipocytes form a single massive lipid droplet that fills almost the entire cell.
"This is crucial for the normal functioning of adipose tissue, although for reasons we do not yet fully understand. However, we do know that this mode of storage is important for the ability of adipocytes to grow when nutrients are available and, conversely, to release fats for the body's use during fasting," Ikonen explains.
The proper storage of lipids is crucial for metabolic health and the new study could lead to new treatments to improve healthy lipid storage, which may reduce the risks of obesity, diabetes, and other metabolic diseases.
Original article
Li C, Sun XN, Funcke JB, Vanharanta L, Prasanna X, Gov K, Li Y, Virostek M, Joung C, Joffin N, Kanerva K, Szkalisity A, Kulig W, Straub L, Chen S, Velasco J, Cobb A, La Padula D, Wang MY, Onodera T, Vörös C, Kim DS, Kim M, Varlamov O, Li Y, Liu C, Nawrocki AR, Zhao S, Oh DY, Wang ZV, Gordillo R, Goodman JM, Wynn RM, Henne WM, Vattulainen I, Han Y, Ikonen E, Scherer PE.
Science. 2025 Nov 6;390(6773):eadr9755. doi: 10.1126/science.adr9755.