Epithelial cells form sheets that line cavities and structures. Their organization and structure are polarized, allowing transport of material from one side of the cell to the other. Earlier this year, investigators reported that galectin-3 plays a role in the establishment of epithelial polarity, possibly through its effects on centrosomes, the primary microtubule-organizing centers. Images above show mammalian cells allowed to grow into a polarized epithelial layer. A protein that is typically on the apical side of the cells (top, green) is mislocalized in cells with lower levels of galectin-3 (bottom). DNA is in blue.
Reference: Annett Koch, Francoise Poirier, Ralf Jacob, and Delphine Delacour. Authors’ Molecular Biology of the Cell paper can be found here.