C. elegans Enabled exhibits novel interactions with N-WASP, Abl, and cell-cell junctions

Area of Science:

• Cell Biology
• Developmental Biology
• Molecular Biology

Background:

• Ena/VASP proteins regulate actin dynamics at leading cell edges.
• Their role in cell-cell junctions and epithelial morphogenesis is less understood.
• UNC-34 is the C. elegans Ena/VASP homolog.

Purpose of the Study:

• To investigate the role of UNC-34/Ena/VASP proteins in C. elegans epidermal morphogenesis.
• To determine the localization and regulation of UNC-34 at cell junctions.
• To explore the relationship between UNC-34, N-WASP, and Abelson kinase in epithelial development.

Main Methods:

• Analysis of embryonic phenotypes in mutants lacking UNC-34 and/or N-WASP.
• Localization studies using GFP-tagged UNC-34.
• Genetic interaction studies involving UNC-34, AJM-1, and Abelson kinase.

Main Results:

• Embryos lacking UNC-34 show subtle defects, but combined loss with N-WASP causes severe epidermal morphogenesis defects.
• UNC-34 localizes to leading edges and redistributes to forming cell junctions.
• Junctional localization of UNC-34 depends on AJM-1, not previously known Ena/VASP regulators.
• Abelson kinase functions in parallel to UNC-34/Ena, antagonizing its function.

Conclusions:

• UNC-34/Ena/VASP proteins play essential, parallel roles with N-WASP in coordinating cell behavior during epidermal morphogenesis.
• AJM-1 mediates UNC-34 localization to cadherin-based junctions.
• Abelson kinase antagonizes UNC-34/Ena function in epithelial development.