Influenza A viruses use multivalent sialic acid clusters for cell binding and receptor activation
Fig 5
Live-cell super-resolution imaging reveals long-lived EGFR clusters in A549 cells.
EGFR coupled to the photo-convertible protein mEos3 was expressed in A549 cells. Subsequent PALM imaging allows to study EGFR distribution in live cells at the single protein level. In the absence of any stimulus, we could detect nanodomains of EGFR within the dorsal and also the ventral plasma membrane (A). Scale bar: left panel, 1 μm. The image in A shows a maximum projected map of single molecule localizations recorded over a period of 10 min. B shows two cluster examples as a cumulative density distribution (upper panel) as well as XY scatter with the colorscale according to time at which the localization was detected (lower panel). While the projection of all localization allows to identify protein clusters, we can use the time information to further estimate the cluster lifetime. As shown in C, cumulative counting of individual localizations within a clustered region gives direct information of the minimum cluster lifetime. D shows the corresponding lifetime distribution of EGFR clusters recorded at the dorsal as well as the ventral side of the cell in the absence of any stimulus.