Emerging roles of lipid transfer protein dimerization.

The unique lipid composition of organelles defines their identity and is fundamental to their function. Lipid transfer proteins perform non-vesicular trafficking of lipids among cellular membranes to maintain their lipid compositions. Lipid transfer protein-mediated lipid trafficking is also essential for creating sub-organellar nano-domains that can recruit functional proteins or change the biophysical properties of membranes. The latest research focusing on the homo- and hetero-dimerization of lipid transfer proteins highlights the functional implications and the clinical significance of these events. Dimerization promotes lipid transfer protein localization at membrane contact sites and mediates the assembly of lipid transfer protein super-complexes to synchronize the transfer of different lipid types between organelles. Meanwhile, abnormal lipid flows caused by disarrangements in lipid transfer protein dimerization disturb organelle lipid landscapes, which has clinical consequences. This Review discusses the latest developments regarding the dimerization of lipid transfer proteins and their adaptor proteins that are critical for lipid trafficking between the organelles of the cell.