The time and energy required to understand any complex process in the cell can be intimidating. Frequently biologists will take a systematic approach, whether that is identifying every protein involved, finding the exact location of proteins, or uncovering every protein-protein interaction, etc. Some biologists combine a few approaches, throw in their own clever spin, and turn out a pretty darn complete picture of what’s going on. With that in mind, enjoy today’s image!
Endocytosis is the uptake of material into the cell, and involves a long list of proteins that are recruited to and dissociated from the membrane in a specific order. A recent paper describes how the combination of fluorescent microscopy and electron microscopy was used to systematically correlate the composition of proteins with the plasma membrane’s shape throughout endocytosis in budding yeast. Kukulski and colleagues used fluorescent tags that correlate with different modules, or stages, of endocytosis to understand how the localizations of proteins overlap over time. Then, these fluorescent tags were used as a guide in electron tomography to visualize the exact structure and shape of the membrane at each module. In the images above, yeast cells have fluorescent tags for the coat module, an intermediate step, of endocytosis (green, Sla1) and a later actin module (red, Abp1). When the two proteins overlap at the membrane, the signal appears yellow. Below each fluorescent image is the corresponding electron tomography image that shows the ultrastructure of the membrane at each stage. The cartoon above shows the time window in endocytosis for each protein.
Wanda Kukulski, Martin Schorb, Marko Kaksonen, & John A.G. Briggs (2012). Plasma Membrane Reshaping during Endocytosis Is Revealed by Time-Resolved Electron Tomography Cell, 150 (3), 508-520 DOI: 10.1016/j.cell.2012.05.046
Copyright ©2012 Elsevier Ltd. All rights reserved.