MAP3K1 integrates RhoA/ROCK signaling to regulate epithelial morphogenesis.

Area of Science:

• Developmental Biology
• Molecular Cell Biology
• Genetics

Background:

• Biological processes depend on complex interactions between genes and the environment.
• Understanding gene-gene (G×G) and gene-environment (G×E) interactions is crucial but challenging.
• Existing models often lack a comprehensive view of integrated signaling networks.

Purpose of the Study:

• To elucidate the molecular mechanisms underlying G×G and G×E interactions in morphogenesis.
• To identify novel signaling components and their integration within known pathways.
• To investigate how genetic and environmental factors converge to regulate developmental processes.

Main Methods:

• Utilized mouse embryonic eyelid closure as a model system for studying morphogenesis.
• Employed TurboID-based proximity proteomics to identify protein interactions.
• Conducted genetic analyses, including single and combined gene deficiencies, and assessed responses to dioxin exposure.

Main Results:

• Identified a RhoA-ROCK signaling branch as a key component integrated with the S1PR-MAP3K1-JNK axis.
• Demonstrated convergence on paxillin phosphorylation and c-Jun activation, linking cytoskeletal dynamics to transcriptional regulation.
• Found that combined RhoA-ROCK deficiency or single-gene loss under specific genetic or environmental stress conditions disrupts eyelid closure.

Conclusions:

• The RhoA-ROCK pathway is an integral module within the MAP3K1 regulatory network.
• This network integrates genetic and environmental inputs to ensure robust embryonic development and morphogenesis.
• The findings provide a deeper understanding of how cells coordinate complex responses to diverse cues.