Review: Single-particle tracking for the quantification of membrane protein dynamics in living plant cells (Mol. Plant)

Real-time tracking is a hugely powerful way to understand the behaviour of single proteins. Cui et al. review the methods and applications of single-particle tracking (SPT) in plant cells. They describe the applications of variable-angle total internal reflection fluorescence microscopy (VA-TIRFM) to visualize fluorescently labeled plasma-membrane proteins.  SPT has revealed many interesting and important aspects of membrane protein dynamics, such as changes in diffusion rate within the plasma membrane in response to activation or ligand binding. Protein oligomerization can also be detected through stepwise fluorescence bleaching, endocytosis can be observed (and dwell-time at the membrane calculated) by disappearance of fluorescent signals from the membrane, and co-localization dynamics between proteins observed. The authors conclude, “It is anticipated that in the near future these approaches will fundamentally change our views of the molecular processes actually occurring in living cells.” Mol. Plant 10.1016/j.molp.2018.09.008