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Updated: Jun 13, 2026
05:50
Measuring Cell-Edge Protrusion Dynamics during Spreading using Live-Cell Microscopy
Published on: November 1, 2021
Sidekick2 facilitates multiciliated cell penetration through multicellular adherens junctions.
Eve E Suva1, Tomohito Higashi2, Brian J Mitchell1,3
1Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University; Chicago, IL, 60611, USA.
Biorxiv : the Preprint Server for Biology
|June 12, 2026
Summary
Sidekick2 (Sdk2) protein at multicellular junctions in embryonic Xenopus laevis regulates epithelial integrity during tissue development. Its intracellular domain is crucial for controlling junction remodeling and cell movement.
Area of Science:
- Developmental Biology
- Cell Biology
- Epithelial Biology
Background:
- Multicellular vertices are key sites for tissue dynamics in epithelia.
- The adhesion protein Sidekick2 (Sdk2) is expressed in vertebrate epithelia.
Purpose of the Study:
- To investigate the role of Sidekick2 (Sdk2) in epithelial tissue dynamics during embryonic development.
- To characterize Sdk2 localization and dynamics at multicellular junctions.
- To determine the functional contribution of Sdk2's intracellular and extracellular domains.
Main Methods:
- Studied embryonic *Xenopus laevis* epithelium during radial intercalation.
- Utilized fluorescence recovery after photobleaching (FRAP) to analyze Sdk2 dynamics.
- Employed domain-specific overexpression to assess functional roles.
Main Results:
- Sdk2 localizes to multicellular adherens junctions in the *Xenopus laevis* embryonic epithelium.
- Sdk2 facilitates the penetration of multiciliated cells into the outer epithelium.
- Overexpression of the Sdk2 intracellular domain, but not the extracellular domain, acts as a dominant negative, delaying radial intercalation.
Conclusions:
- Sdk2's intracellular interactions are critical for regulating junctional remodeling during radial intercalation.
- Sdk2 is implicated as a component of multicellular vertices that maintains epithelial integrity.
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