Fig. 3: Transmission electron microscopy (TEM) of negative stained mGSDMA3Nterm oligomers inserted into liposomes made from E. coli polar lipid extract.
From: Gasdermin-A3 pore formation propagates along variable pathways
a–i TEM images of liposomes after incubation with mGSDMA3 in the presence of TEV. Upon adsorption onto TEM grids the liposomes fused into membrane patches that spread out over the carbon film. Most mGSDMA3Nterm oligomers inserted into the lipid membranes appear ring-shaped but arc-shaped (black arrows) and slits-shaped (white arrows) oligomers are observed as well. Suspended liposomes made from E. coli polar lipid extract were incubated overnight at 37 °C with 7 μM mGSDMA3 and 1.5 µM TEV. j–l TEM images showing large vesicles fused on the carbon film from empty E. coli polar lipid liposomes (j), from liposomes incubated with mGSDMA3 (7 μM) (k), and from liposomes incubated with TEV (1.5 μM) (l). m The mixture of mGSDMA3 and TEV incubated in the absence of liposomes exhibits a granular appearance. None of the samples (j–m) showed arc‐, slit‐, or ring‐shaped oligomers as observed for mGSDMA3Nterm incubated with liposomes. All samples (a–m) were incubated overnight at 37 °C, adsorbed to glow-discharged carbon coated grids, negatively stained with uranyl acetate and imaged at 120 kV (Methods). Scale bars, 100 nm (a–i) and 200 nm (j–m).
