Dynamics of core planar polarity protein turnover and stable assembly into discrete membrane subdomains.
Bottom Line: The core planar polarity proteins localize asymmetrically to the adherens junctions of epithelial cells, where they have been hypothesized to assemble into intercellular complexes.Here, we show that the core proteins are preferentially distributed to discrete membrane subdomains ("puncta"), where they form asymmetric contacts between neighboring cells.Thus, we define the distinct roles of specific core proteins in the formation of asymmetric contacts between cells, which is a key event in the generation of coordinated cellular asymmetry.
Affiliation: MRC Centre for Developmental and Biomedical Genetics, and Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.Show MeSH
Related in: MedlinePlus
Mentions: In both flies and vertebrates, the core proteins localize asymmetrically within cells prior to morphological signs of polarization (Rida and Chen, 2009; Roszko et al., 2009; Strutt and Strutt, 2009; Hashimoto and Hamada, 2010). In the Drosophila early pupal wing, asymmetric localization is seen within the adherens junction region, oriented toward the wing margin (Classen et al., 2005; Aigouy et al., 2010). Cell rearrangements then lead to a remodeling of asymmetry, such that it aligns on the proximodistal (PD) axis (Aigouy et al., 2010). Consequently, at the time that trichomes emerge, the seven-pass transmembrane protein Frizzled (Fz) localizes distally, together with the cytoplasmic proteins Dishevelled (Dsh) and Diego (Dgo), whereas the transmembrane protein Strabismus (Stbm, also known as Van Gogh) and the cytoplasmic protein Prickle (Pk) localize proximally, and the seven-pass transmembrane cadherin Flamingo (Fmi, also known as Starry Night) localizes both proximally and distally (Figure 1A; reviewed in Strutt and Strutt, 2009).
Affiliation: MRC Centre for Developmental and Biomedical Genetics, and Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.