Loss of Ena/VASP interferes with lamellipodium architecture, motility and integrin-dependent adhesion
- Hannover Medical School, Germany
- CytoMorphoLab, France
- Institute of Science and Technology Austria (IST Austria), Austria
- Technische Universität Braunschweig, Germany
- Interdisciplinary Research Institute Grenoble, France
Abstract
Cell migration entails networks and bundles of actin filaments termed lamellipodia and microspikes or filopodia, respectively, as well as focal adhesions, all of which recruit Ena/VASP family members hitherto thought to antagonize efficient cell motility. However, we find these proteins to act as positive regulators of migration in different murine cell lines. CRISPR/Cas9-mediated loss of Ena/VASP proteins reduced lamellipodial actin assembly and perturbed lamellipodial architecture, as evidenced by changed network geometry as well as reduction of filament length and number that was accompanied by abnormal Arp2/3 complex and heterodimeric capping protein accumulation. Loss of Ena/VASP function also abolished the formation of microspikes normally embedded in lamellipodia, but not of filopodia capable of emanating without lamellipodia. Ena/VASP-deficiency also impaired integrin-mediated adhesion accompanied by reduced traction forces exerted through these structures. Our data thus uncover novel Ena/VASP functions of these actin polymerases that are fully consistent with their promotion of cell migration.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting files. Source data files have been provided for all Figures.
Article and author information
Author details
Funding
Deutsche Forschungsgemeinschaft (FA 330/11-1)
- Jan Faix
H2020 European Research Council (AAA 741773)
- Laurent Blanchoin
H2020 European Research Council (CoG 724373)
- Michael Sixt
Deutsche Forschungsgemeinschaft (RO2414/5-1)
- Klemens Rottner
Technische Universität Braunschweig (GRK2223/1)
- Klemens Rottner
Austrian Science Fund
- Michael Sixt
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Pekka Lappalainen, University of Helsinki, Finland
Publication history
- Received: January 21, 2020
- Accepted: May 8, 2020
- Accepted Manuscript published: May 11, 2020 (version 1)
- Version of Record published: May 20, 2020 (version 2)
Copyright
© 2020, Damiano- Guercio et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 2,829
- Page views
-
- 497
- Downloads
-
- 38
- Citations
Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Loss of Ena/VASP interferes with lamellipodium architecture, motility and integrin-dependent adhesion
eLife 9:e55351.
https://doi.org/10.7554/eLife.55351
Further reading
-
- Cell Biology
The specific functional properties of a tissue are distributed amongst its component cell types. The various cells act coherently, as an ensemble, in order to execute a physiologic response. Modern approaches for identifying and dissecting novel physiologic mechanisms would benefit from an ability to identify specific cell types in live tissues that could then be imaged in real-time. Current techniques require the use of fluorescent genetic reporters that are not only cumbersome, but which only allow the simultaneous study of 3 or 4 cell types at a time. We report a non-invasive imaging modality that capitalizes on the endogenous autofluorescence signatures of the metabolic cofactors NAD(P)H and FAD. By marrying morphological characteristics with autofluorescence signatures, all seven of the airway epithelial cell types can be distinguished simultaneously in mouse tracheal explant in real-time. Furthermore, we find that this methodology for direct cell type specific identification avoids pitfalls associated with the use of ostensibly cell type-specific markers that are, in fact, altered by clinically relevant physiologic stimuli. Finally, we utilize this methodology to interrogate real-time physiology and identify dynamic secretory cell associated antigen passages (SAPs) that form in response to cholinergic stimulus. The identical process has been well documented in the intestine where the dynamic formation of secretory and goblet cell associated antigen passages (SAPs and GAPs) enable luminal antigen sampling. Given that airway secretory cells can be stimulated to make mucous within hours, we suspect that both SAPs and GAPs are also used for luminal antigen sampling in the airway. This hypothesis is supported by our observation that secretory cells with airway SAPs are frequently juxtaposed to antigen presenting cells.
-
- Cell Biology
Endothelial cells line all blood vessels, where they coordinate blood vessel formation and the blood-tissue barrier via regulation of cell-cell junctions. The nucleus also regulates endothelial cell behaviors, but it is unclear how the nucleus contributes to endothelial cell activities at the cell periphery. Here, we show that the nuclear-localized linker of the nucleoskeleton and cytoskeleton (LINC) complex protein SUN1 regulates vascular sprouting and endothelial cell-cell junction morphology and function. Loss of murine endothelial Sun1 impaired blood vessel formation and destabilized junctions, angiogenic sprouts formed but retracted in SUN1-depleted sprouts, and zebrafish vessels lacking Sun1b had aberrant junctions and defective cell-cell connections. At the cellular level, SUN1 stabilized endothelial cell-cell junctions, promoted junction function, and regulated contractility. Mechanistically, SUN1 depletion altered cell behaviors via the cytoskeleton without changing transcriptional profiles. Reduced peripheral microtubule density, fewer junction contacts, and increased catastrophes accompanied SUN1 loss, and microtubule depolymerization phenocopied effects on junctions. Depletion of GEF-H1, a microtubule-regulated Rho activator, or the LINC complex protein nesprin-1 rescued defective junctions of SUN1-depleted endothelial cells. Thus, endothelial SUN1 regulates peripheral cell-cell junctions from the nucleus via LINC complex-based microtubule interactions that affect peripheral microtubule dynamics and Rho-regulated contractility, and this long-range regulation is important for proper blood vessel sprouting and junction integrity.
