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The mammalian Scribble polarity protein regulates epithelial cell adhesion and migration through E-cadherin.

Qin Y, Capaldo C, Gumbiner BM, Macara IG - J. Cell Biol. (2005)

Bottom Line: These effects are independent of Rac activation or Scrib binding to betaPIX.Rather, Scrib depletion disrupts E-cadherin-mediated cell-cell adhesion.Adhesion is partially rescued by expression of an E-cadherin-alpha-catenin fusion protein but not by E-cadherin-green fluorescent protein.

View Article: PubMed Central - PubMed

Affiliation: Center for Cell Signaling, Department of Microbiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.

ABSTRACT
Scribble (Scrib) is a conserved polarity protein required in Drosophila melanogaster for synaptic function, neuroblast differentiation, and epithelial polarization. It is also a tumor suppressor. In rodents, Scrib has been implicated in receptor recycling and planar polarity but not in apical/basal polarity. We now show that knockdown of Scrib disrupts adhesion between Madin-Darby canine kidney epithelial cells. As a consequence, the cells acquire a mesenchymal appearance, migrate more rapidly, and lose directionality. Although tight junction assembly is delayed, confluent monolayers remain polarized. These effects are independent of Rac activation or Scrib binding to betaPIX. Rather, Scrib depletion disrupts E-cadherin-mediated cell-cell adhesion. The changes in morphology and migration are phenocopied by E-cadherin knockdown. Adhesion is partially rescued by expression of an E-cadherin-alpha-catenin fusion protein but not by E-cadherin-green fluorescent protein. These results suggest that Scrib stabilizes the coupling between E-cadherin and the catenins and are consistent with the idea that mammalian Scrib could behave as a tumor suppressor by regulating epithelial cell adhesion and migration.

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Cells lacking Scrib lose their epithelial morphology at low density. (A) Control (Luc) and ScrbKD cells were grown on 6-well plates at low density for 3 d. Images were obtained by phase-contrast microscopy using a 10× objective. (B) Control and ScrbKD cells were fixed and stained with phalloidin to visualize F-actin. Typical colonies are shown. (C) Surface areas per cell (μm2) were measured for 80–90 frames (as shown in A) and sorted into bins 200 μm2 wide. The percentage of cells in each bin is shown.
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fig2: Cells lacking Scrib lose their epithelial morphology at low density. (A) Control (Luc) and ScrbKD cells were grown on 6-well plates at low density for 3 d. Images were obtained by phase-contrast microscopy using a 10× objective. (B) Control and ScrbKD cells were fixed and stained with phalloidin to visualize F-actin. Typical colonies are shown. (C) Surface areas per cell (μm2) were measured for 80–90 frames (as shown in A) and sorted into bins 200 μm2 wide. The percentage of cells in each bin is shown.

Mentions: When cells were transfected with pS-ScrbKD vectors and plated at low densities, they consistently displayed a mesenchymal phenotype. Normal MDCK cells organize into discrete, tight islands with smooth boundaries, but cells lacking Scrib appeared more fibroblastic (Fig. 2, A and B). They spread over a much larger surface area (approximately three to five times larger; Fig. 2 C), and the edges of the cell clusters were disorganized as though the cells were moving apart from one another. When stained with phalloidin, the normal cortical actin rings were absent in cells lacking SCRIB and were replaced by stress fibers often oriented along the long axis of the cells (Fig. 2 B). These observations suggested that Scrib might regulate epithelial cell adhesion and/or migration.


The mammalian Scribble polarity protein regulates epithelial cell adhesion and migration through E-cadherin.

Qin Y, Capaldo C, Gumbiner BM, Macara IG - J. Cell Biol. (2005)

Cells lacking Scrib lose their epithelial morphology at low density. (A) Control (Luc) and ScrbKD cells were grown on 6-well plates at low density for 3 d. Images were obtained by phase-contrast microscopy using a 10× objective. (B) Control and ScrbKD cells were fixed and stained with phalloidin to visualize F-actin. Typical colonies are shown. (C) Surface areas per cell (μm2) were measured for 80–90 frames (as shown in A) and sorted into bins 200 μm2 wide. The percentage of cells in each bin is shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2171311&req=5

fig2: Cells lacking Scrib lose their epithelial morphology at low density. (A) Control (Luc) and ScrbKD cells were grown on 6-well plates at low density for 3 d. Images were obtained by phase-contrast microscopy using a 10× objective. (B) Control and ScrbKD cells were fixed and stained with phalloidin to visualize F-actin. Typical colonies are shown. (C) Surface areas per cell (μm2) were measured for 80–90 frames (as shown in A) and sorted into bins 200 μm2 wide. The percentage of cells in each bin is shown.
Mentions: When cells were transfected with pS-ScrbKD vectors and plated at low densities, they consistently displayed a mesenchymal phenotype. Normal MDCK cells organize into discrete, tight islands with smooth boundaries, but cells lacking Scrib appeared more fibroblastic (Fig. 2, A and B). They spread over a much larger surface area (approximately three to five times larger; Fig. 2 C), and the edges of the cell clusters were disorganized as though the cells were moving apart from one another. When stained with phalloidin, the normal cortical actin rings were absent in cells lacking SCRIB and were replaced by stress fibers often oriented along the long axis of the cells (Fig. 2 B). These observations suggested that Scrib might regulate epithelial cell adhesion and/or migration.

Bottom Line: These effects are independent of Rac activation or Scrib binding to betaPIX.Rather, Scrib depletion disrupts E-cadherin-mediated cell-cell adhesion.Adhesion is partially rescued by expression of an E-cadherin-alpha-catenin fusion protein but not by E-cadherin-green fluorescent protein.

View Article: PubMed Central - PubMed

Affiliation: Center for Cell Signaling, Department of Microbiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA.

ABSTRACT
Scribble (Scrib) is a conserved polarity protein required in Drosophila melanogaster for synaptic function, neuroblast differentiation, and epithelial polarization. It is also a tumor suppressor. In rodents, Scrib has been implicated in receptor recycling and planar polarity but not in apical/basal polarity. We now show that knockdown of Scrib disrupts adhesion between Madin-Darby canine kidney epithelial cells. As a consequence, the cells acquire a mesenchymal appearance, migrate more rapidly, and lose directionality. Although tight junction assembly is delayed, confluent monolayers remain polarized. These effects are independent of Rac activation or Scrib binding to betaPIX. Rather, Scrib depletion disrupts E-cadherin-mediated cell-cell adhesion. The changes in morphology and migration are phenocopied by E-cadherin knockdown. Adhesion is partially rescued by expression of an E-cadherin-alpha-catenin fusion protein but not by E-cadherin-green fluorescent protein. These results suggest that Scrib stabilizes the coupling between E-cadherin and the catenins and are consistent with the idea that mammalian Scrib could behave as a tumor suppressor by regulating epithelial cell adhesion and migration.

Show MeSH
Related in: MedlinePlus