Abstract:

Plants frequently include subcellular organelles called lipid droplets, which encapsulate a range of lipids and store them in the cytoplasm. Lipid droplets involved in the control of lipid metabolism are crucial for maintaining plant lipid homeostasis. As the most important outer membrane protein of lipid droplets, caleosin plays a critical role in the formation and stabilization of lipid droplets as well as the accumulation of secondary metabolites and lipids. A thorough knowledge of caleosin regulating lipid droplet may provide as a foundation for further investigating lipid homeostasis and secondary metabolic processes related to lipid droplets. This paper presents the structure of plant caleosin, and highlights the significant elements and potential function in their protein sequences. We reviewed the species-specificity and tissue-specificity of the caleosin gene family, showing that not only the gene function of caleosin varies throughout the terrestrial plant evolutionary process, also its specific biological function varies among different tissues. Subsequently we summarized recent research on caleosin's influence on lipid droplet biosynthesis and clarified its function in triggering lipid droplet biosynthesis in response to environmental stimuli. This review indicates that caleosin’s ability to regulate lipid droplet metabolism is associated with the stabilizing influence of the protein's N-terminal sequence on lipid droplet structure. Furthermore, using aflatoxin, paclitaxel, and rutin as examples, we discussed the impact of caleosin on the accumulation of secondary metabolites encapsulated in lipid droplets. Concluding by discussing the prospects of gene editing technology and the application of artificial oil bodies, we aim to provide references for the scientific investigation of the mechanism of lipid quality formation and lipid homeostasis.

Key words: caleosin, lipid droplets, protein structure, membrane protein, secondary metabolites, protein family, lipid homeostasis