Correlative light and electron microscopy reveals fork-shaped structures at actin entry sites of focal adhesions

Karin Legerstee, Jason Sueters, Tsion E. Abraham, Johan A. Slotman, Gert Jan Kremers, Jacob P. Hoogenboom, Adriaan B. Houtsmuller*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
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Focal adhesions (FAs) are the main cellular structures to link the intracellular cytoskeleton to the extracellular matrix. FAs mediate cell adhesion, are important for cell migration and are involved in many (patho)-physiological processes. Here we examined FAs and their associated actin fibres using correlative fluorescence and scanning electron microscopy (SEM). We used fluorescence images of cells expressing paxillin-GFP to define the boundaries of FA complexes in SEM images, without using SEM contrast enhancing stains. We observed that SEM contrast was increased around the actin fibre entry site in 98% of FAs, indicating increases in protein density and possibly also phosphorylation levels in this area. In nearly three quarters of the FAs, these nanostructures had a fork shape, with the actin forming the stem and the high-contrast FA areas the fork. In conclusion, the combination of fluorescent and electron microscopy allowed accurate localisation of a highly abundant, novel fork structure at the FA-actin interface.

Original languageEnglish
JournalBiology Open
Issue number11
Publication statusPublished - 21 Nov 2022

Bibliographical note

Open Access funding provided by Erasmus Universiteit Rotterdam. Deposited in
PMC for immediate release.

Publisher Copyright:
© 2022. Published by The Company of Biologists Ltd.


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