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Binding site for p120/delta-catenin is not required for Drosophila E-cadherin function in vivo.

Pacquelet A, Lin L, Rorth P - J. Cell Biol. (2003)

Bottom Line: As expected, DE-cadherin-Delta beta did not substitute for DE-cadherin in these processes, although it retained some residual activity.Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations.Thus, interaction with p120/delta-catenin does not appear to be required for DE-cadherin function in vivo.

View Article: PubMed Central - PubMed

Affiliation: European Molecular Biology Laboratory, 69117 Heidelberg, Germany.

ABSTRACT
Homophilic cell adhesion mediated by classical cadherins is important for many developmental processes. Proteins that interact with the cytoplasmic domain of cadherin, in particular the catenins, are thought to regulate the strength and possibly the dynamics of adhesion. beta-catenin links cadherin to the actin cytoskeleton via alpha-catenin. The role of p120/delta-catenin proteins in regulating cadherin function is less clear. Both beta-catenin and p120/delta-catenin are conserved in Drosophila. Here, we address the importance of cadherin-catenin interactions in vivo, using mutant variants of Drosophila epithelial cadherin (DE-cadherin) that are selectively defective in p120ctn (DE-cadherin-AAA) or beta-catenin-armadillo (DE-cadherin-Delta beta) interactions. We have analyzed the ability of these proteins to substitute for endogenous DE-cadherin activity in multiple cadherin-dependent processes during Drosophila development and oogenesis; epithelial integrity, follicle cell sorting, oocyte positioning, as well as the dynamic adhesion required for border cell migration. As expected, DE-cadherin-Delta beta did not substitute for DE-cadherin in these processes, although it retained some residual activity. Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations. Thus, interaction with p120/delta-catenin does not appear to be required for DE-cadherin function in vivo.

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Cortical recruitment of p120ctn and β-catenin by DE-cadherin variants in Schneider cells. (A) Schematic representation of DE-cadherin variants and catenins associated. (B) Immunoprecipitation from Schneider cells transfected with pRm-HA-p120ctn and pRm-DE-cadherin-wt or pUAST-DE-cadherin-AAA+pRmGal4. 4% of lysates and all immunoprecipitates (IP) were loaded. (C–H) Schneider cells transfected with pRm-HA-p120ctn (C–E, green, and C''–E'') or pRm-β-catenin (F–H, green, and F''–H''), and pRm-DE-cadherin-wt (C and F), pRm-DE-cadherin-AAA (D and G), or pRm-DE-cadherin-Δβ (E and H, red, and C'–H'). HA-p120ctn was often enriched at the cortex between two cadherin overexpressing cells, suggesting that recruitment to the membrane is affected by cadherin interactions. Bars, ∼5 μm.
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fig1: Cortical recruitment of p120ctn and β-catenin by DE-cadherin variants in Schneider cells. (A) Schematic representation of DE-cadherin variants and catenins associated. (B) Immunoprecipitation from Schneider cells transfected with pRm-HA-p120ctn and pRm-DE-cadherin-wt or pUAST-DE-cadherin-AAA+pRmGal4. 4% of lysates and all immunoprecipitates (IP) were loaded. (C–H) Schneider cells transfected with pRm-HA-p120ctn (C–E, green, and C''–E'') or pRm-β-catenin (F–H, green, and F''–H''), and pRm-DE-cadherin-wt (C and F), pRm-DE-cadherin-AAA (D and G), or pRm-DE-cadherin-Δβ (E and H, red, and C'–H'). HA-p120ctn was often enriched at the cortex between two cadherin overexpressing cells, suggesting that recruitment to the membrane is affected by cadherin interactions. Bars, ∼5 μm.

Mentions: Classic cadherins are major mediators of homophilic cell–cell adhesion during animal development (Tepass, 1999). In many developmental processes, cadherin-dependent adhesive interactions between cells need to be regulated. The question of how such regulation is achieved is of considerable interest. Cell culture studies have shown that both clustering of cadherin molecules and linkage to the actin cytoskeleton dramatically affect the strength of adhesion. The link between the intracellular domain of cadherin and the actin cytoskeleton is provided by proteins of the catenin family; β-catenin binds to the COOH-terminal part of the cadherin intracellular domain and to α-catenin, which in turn links to the actin cytoskeleton by interacting with multiple proteins (Fig. 1 A). In addition, members of the p120/δ-catenin family of proteins can bind to the juxtamembrane domain of cadherin. In vitro studies have suggested that p120/δ-catenin proteins are regulators of cadherin-dependent adhesion, although there is some controversy on whether they are positive or negative regulators (Anastasiadis and Reynolds, 2000).


Binding site for p120/delta-catenin is not required for Drosophila E-cadherin function in vivo.

Pacquelet A, Lin L, Rorth P - J. Cell Biol. (2003)

Cortical recruitment of p120ctn and β-catenin by DE-cadherin variants in Schneider cells. (A) Schematic representation of DE-cadherin variants and catenins associated. (B) Immunoprecipitation from Schneider cells transfected with pRm-HA-p120ctn and pRm-DE-cadherin-wt or pUAST-DE-cadherin-AAA+pRmGal4. 4% of lysates and all immunoprecipitates (IP) were loaded. (C–H) Schneider cells transfected with pRm-HA-p120ctn (C–E, green, and C''–E'') or pRm-β-catenin (F–H, green, and F''–H''), and pRm-DE-cadherin-wt (C and F), pRm-DE-cadherin-AAA (D and G), or pRm-DE-cadherin-Δβ (E and H, red, and C'–H'). HA-p120ctn was often enriched at the cortex between two cadherin overexpressing cells, suggesting that recruitment to the membrane is affected by cadherin interactions. Bars, ∼5 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2172659&req=5

fig1: Cortical recruitment of p120ctn and β-catenin by DE-cadherin variants in Schneider cells. (A) Schematic representation of DE-cadherin variants and catenins associated. (B) Immunoprecipitation from Schneider cells transfected with pRm-HA-p120ctn and pRm-DE-cadherin-wt or pUAST-DE-cadherin-AAA+pRmGal4. 4% of lysates and all immunoprecipitates (IP) were loaded. (C–H) Schneider cells transfected with pRm-HA-p120ctn (C–E, green, and C''–E'') or pRm-β-catenin (F–H, green, and F''–H''), and pRm-DE-cadherin-wt (C and F), pRm-DE-cadherin-AAA (D and G), or pRm-DE-cadherin-Δβ (E and H, red, and C'–H'). HA-p120ctn was often enriched at the cortex between two cadherin overexpressing cells, suggesting that recruitment to the membrane is affected by cadherin interactions. Bars, ∼5 μm.
Mentions: Classic cadherins are major mediators of homophilic cell–cell adhesion during animal development (Tepass, 1999). In many developmental processes, cadherin-dependent adhesive interactions between cells need to be regulated. The question of how such regulation is achieved is of considerable interest. Cell culture studies have shown that both clustering of cadherin molecules and linkage to the actin cytoskeleton dramatically affect the strength of adhesion. The link between the intracellular domain of cadherin and the actin cytoskeleton is provided by proteins of the catenin family; β-catenin binds to the COOH-terminal part of the cadherin intracellular domain and to α-catenin, which in turn links to the actin cytoskeleton by interacting with multiple proteins (Fig. 1 A). In addition, members of the p120/δ-catenin family of proteins can bind to the juxtamembrane domain of cadherin. In vitro studies have suggested that p120/δ-catenin proteins are regulators of cadherin-dependent adhesion, although there is some controversy on whether they are positive or negative regulators (Anastasiadis and Reynolds, 2000).

Bottom Line: As expected, DE-cadherin-Delta beta did not substitute for DE-cadherin in these processes, although it retained some residual activity.Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations.Thus, interaction with p120/delta-catenin does not appear to be required for DE-cadherin function in vivo.

View Article: PubMed Central - PubMed

Affiliation: European Molecular Biology Laboratory, 69117 Heidelberg, Germany.

ABSTRACT
Homophilic cell adhesion mediated by classical cadherins is important for many developmental processes. Proteins that interact with the cytoplasmic domain of cadherin, in particular the catenins, are thought to regulate the strength and possibly the dynamics of adhesion. beta-catenin links cadherin to the actin cytoskeleton via alpha-catenin. The role of p120/delta-catenin proteins in regulating cadherin function is less clear. Both beta-catenin and p120/delta-catenin are conserved in Drosophila. Here, we address the importance of cadherin-catenin interactions in vivo, using mutant variants of Drosophila epithelial cadherin (DE-cadherin) that are selectively defective in p120ctn (DE-cadherin-AAA) or beta-catenin-armadillo (DE-cadherin-Delta beta) interactions. We have analyzed the ability of these proteins to substitute for endogenous DE-cadherin activity in multiple cadherin-dependent processes during Drosophila development and oogenesis; epithelial integrity, follicle cell sorting, oocyte positioning, as well as the dynamic adhesion required for border cell migration. As expected, DE-cadherin-Delta beta did not substitute for DE-cadherin in these processes, although it retained some residual activity. Surprisingly, DE-cadherin-AAA was able to substitute for the wild-type protein in all contexts with no detectable perturbations. Thus, interaction with p120/delta-catenin does not appear to be required for DE-cadherin function in vivo.

Show MeSH
Related in: MedlinePlus