An Actomyosin-Arf-GEF Negative Feedback Loop for Tissue Elongation under Stress
Junior J West1, Teresa Zulueta-Coarasa2, Janna A Maier1
1Department of Cell & Systems Biology, University of Toronto, 25 Harbord Street, Toronto, ON M5S 3G5, Canada.
Current Biology : CB
|July 25, 2017
Summary
Cytohesins, like Steppke, are crucial for animal tissue elongation under stress by inhibiting actomyosin activity. This discovery reveals a negative feedback loop essential for preventing tissue tears during development.
Area of Science:
- Developmental Biology
- Cellular Mechanics
- Molecular Regulation
Background:
- Animal development involves tissue stretching due to localized contractions.
- Actomyosin activity drives these contractions, but its regulation of tissue physical properties under stress is unclear.
Purpose of the Study:
- To investigate the molecular mechanisms regulating tissue elongation under mechanical stress.
- To identify key proteins involved in controlling tissue tension during development.
Main Methods:
- Utilized Drosophila dorsal closure and zebrafish epiboly models.
- Employed protein localization, laser ablation, and genetic interaction studies.
- Performed live imaging to observe protein dynamics.
Main Results:
- Cytohesins, specifically Steppke, are essential for tissue elongation under stress.
- Steppke inhibits actomyosin activity at adherens junctions, reducing tissue tension.
- Loss of Steppke leads to embryogenesis failure due to myosin misregulation and tissue tears.
- Actomyosin network assembly triggers rapid, localized Steppke accumulation.
Conclusions:
- A rapid negative feedback loop involving cytohesins (Steppke) attenuates tissue tension.
- This mechanism allows for orderly tissue elongation under mechanical stress during animal development.
- Identified a novel molecular pathway regulating tissue physical properties in response to force.
Keywords:
Arf small G proteinDrosophilaactomyosincytohesindorsal closureepibolymorphogenesisnegative feedbacktissue relaxationzebrafishMore Related Videos
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