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Tyrosine-Based Signals Regulate the Assembly of Daple⋅PARD3 Complex at Cell-Cell Junctions.
Jason Ear1, Anokhi Saklecha1, Navin Rajapakse1
1Department of Cellular and Molecular Medicine, University of California San Diego, 9500 Gilman Drive (MC 0651), George E. Palade Bldg, Rm 331-333, La Jolla, CA 92093, USA.
Iscience
|February 15, 2020
Summary
The protein Daple acts as a cellular compass, guiding planar cell polarity establishment and maintenance. Its interaction with PARD3 is regulated by tyrosine phosphorylation, enabling signal integration in cell migration.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Polarized distribution of cellular components is crucial for cell function and often disrupted in disease.
- Planar cell migration involves orientation triggered by cell-cell contact, a process known as planar cell polarity.
Purpose of the Study:
- To investigate the role of the protein Daple (CCDC88C) in establishing and maintaining contact-triggered planar polarity in epithelial cells.
- To elucidate the molecular mechanisms underlying Daple's function in planar cell polarity, including its interactions and regulation.
Main Methods:
- Immunofluorescence microscopy to visualize Daple localization at cell junctions.
- Co-immunoprecipitation assays to study the interaction between Daple and PARD3.
- Site-directed mutagenesis to investigate the role of Daple's PDZ-binding motif (PBM).
- Analysis of tyrosine phosphorylation status of Daple using phospho-specific antibodies and mass spectrometry.
Main Results:
- Daple localizes to cell junctions and functions as a cellular compass for planar cell polarity.
- Daple interacts with the polarity regulator PARD3 via its PBM and PARD3's PDZ domain.
- Tyrosine phosphorylation of Daple's PBM by kinases like Src modulates its interaction with PARD3.
- Hypophosphorylation enhances the Daple-PARD3 interaction, while hyperphosphorylation disrupts it.
Conclusions:
- Daple is a key regulator of contact-triggered planar cell polarity in epithelial cells.
- The Daple-PARD3 interaction is dynamically regulated by tyrosine phosphorylation, revealing Daple's role in signal integration.
- Daple acts as a platform for sensing tyrosine-based signals within the planar cell polarity pathway, impacting cell migration and potentially disease states.
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