1. TES-1/Tes protects junctional actin networks under tension from self-injury during epidermal morphogenesis in the C. elegans embryo
- Author
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Block Sd, Jeff Hardin, Jonathan D. Winkelman, Margaret L. Gardel, Lucas Bg, Anjon Audhya, Allison M. Lynch, and Martin Sc
- Subjects
Stress fiber ,biology ,Chemistry ,Embryonic morphogenesis ,Mutant ,Actin cytoskeleton ,biology.organism_classification ,Embryonic stem cell ,Actin ,Caenorhabditis elegans ,LIM domain ,Cell biology - Abstract
During embryonic morphogenesis, the integrity of epithelial tissues depends on the ability of cells in tissue sheets to undergo rapid changes in cell shape while preventing self-injury to junctional actin networks. LIM domain-containing repeat (LCR) proteins are recruited to sites of strained actin filaments in cultured cells [1–3], and are therefore promising candidates for mediating self-healing of actin networks, but whether they play similar roles in living organisms has not been determined. Here, we establish roles for Caenorhabditis elegans TES-1/Tes, an actin-binding LCR protein present at apical junctions, during epithelial morphogenesis. TES-1::GFP is recruited to apical junctions during embryonic elongation, when junctions are under tension; in embryos in which stochastic failure of cell elongation occurs, TES-1 is only strongly recruited to junctions in cells that successfully elongate, and recruitment is severely compromised in genetic backgrounds in which cell shape changes do not successfully occur. tes-1 mutant embryos display junctional F-actin defects, and loss of TES-1 strongly enhances tension-dependent injury of junctional actin networks in hypomorphic mutant backgrounds for CCC components, suggesting that TES-1 helps to prevent self-injury of junctional actin networks during rapid cell shape change. Consistent with such role, a fragment of TES-1 containing its LIM domains localizes to stress fiber strain sites (SFSS) in cultured vertebrate cells. Together, these data establish TES-1 as a tension-sensitive stabilizer of the junctional actin cytoskeleton during embryonic morphogenesis.
- Published
- 2021
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