Equal distribution of lipid droplets in daughter cells is regulated by microtubules.

During eukaryotic cell division, organelles are distributed between daughter cells through a dynamic process to ensure that cells can differentiate and perform their functions correctly. Uncovering the mode of lipid droplet (LD) distribution may help reveal the mechanism of membrane remodeling during cell division and lipid droplet function. Our results showed that LDs were equally distributed in both daughter cells during cytokinesis. Further experiments demonstrated that the key factor regulating the movement of LDs is the microtubule (MT)-resident protein KIF5B. Because the KIF5B structure lacks a hydrophilic region, we believe that there are proteins that mediate the interaction between LDs and KIF5B. Mass spectrometric detection of KIF5B-interacting proteins on the surface of LDs demonstrated that LDs were first wrapped by intermediate filaments forming a meshwork and then contacted with MTs to mediate lipid droplet movement during cytokinesis. Disruption of the homogeneous distribution of LDs may hinder cell proliferation and even lead to apoptosis.