Real‐time imaging of plasma membrane deformations reveals pre‐fusion membrane curvature changes and a role for dynamin in the regulation of fusion pore expansion
Year: 2012
Type: review
Abstract: Assays for real-time investigation of exocytosis typically measure what is released from the granule. From this, inferences are made about the dynamics of membrane remodeling as fusion progresses from start to finish. We have recently undertaken a different approach to investigate the fusion process, by focusing not primarily on the granule, but rather its partner in exocytosis - the plasma membrane. We have been guided by the idea that biochemical interactions between the granule and plasma membranes before and during fusion, cause changes in membrane conformation. To enable study of membrane conformation, a novel imaging technique was developed combining polarized excitation of an oriented membrane probe 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (diI) with total internal reflection fluorescence microscopy (pTIRFM). Because this technique measures changes in membrane conformation (or deformations) directly, its usefulness persists even after granule cargo reporter (catecholamine, or protein), is no longer present. In this mini-review, we first summarize the workings of pTIRFM. We then discuss the application of the technique to investigate deformations in the membrane preceding fusion, and later, during fusion pore expansion. Finally, we discuss how expansion of the fusion pore may be regulated by the GTPase activity of dynamin.
Source: Journal of Neurochemistry
Institutions: Wayne State University, University of Michigan
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: bronze
Awards: G1698256550, G2677439487, Postdoctoral Training in the Biology of Drug Abuse, Secretion-associated dynamic of the plasma membrane, G7212245019, New optical approaches to study secretory granule structure and function, The Plasma Membrane-Granule Interface in Exocytosis, G846761258, G9000175576
OpenAlex ID: W1577535950