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Requirement of the juxtamembrane domain of the cadherin cytoplasmic tail for morphogenetic cell rearrangement during myotome development.

Horikawa K, Takeichi M - J. Cell Biol. (2001)

Bottom Line: However, a triple alanine substitution in the JM domain, which specifically inhibited the p120ctn binding, had no effect on myotome development.Furthermore, a dominant negative N-cadherin, which had a deletion at the extracellular domain but maintained the normal cytoplasmic tail, did not affect myotome expansion; although it disrupted intersomite boundaries.Overexpression of p120ctn also did not affect myotome expansion, but it did perturb myofiber orientation.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.

ABSTRACT
During development, the activity of cadherin cell adhesion molecules is assumed to be regulated to allow for cell rearrangement or translocation. Previous studies suggest that the juxtamembrane (JM) domain of the cadherin cytoplasmic tail, which contains the site for binding to p120ctn, has a regulatory function in this adhesion system. To study the possible role of JM domain-dependent cadherin regulation in embryonic cell rearrangement, we ectopically expressed a series of N-cadherin mutants in developing somites of chicken embryos. When a JM domain-deficient N-cadherin was expressed, the morphogenetic expansion of the myotome was strongly suppressed. However, a triple alanine substitution in the JM domain, which specifically inhibited the p120ctn binding, had no effect on myotome development. Furthermore, a dominant negative N-cadherin, which had a deletion at the extracellular domain but maintained the normal cytoplasmic tail, did not affect myotome expansion; although it disrupted intersomite boundaries. Overexpression of p120ctn also did not affect myotome expansion, but it did perturb myofiber orientation. These and other observations suggest that the JM domain of N-cadherin has a regulatory role in myotome cell rearrangement in which molecules other than p120ctn are involved. The p120ctn molecule itself seems to play a critical role in the arrangement of myofibers.

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Effects of expression of other cadherin or p120ctn constructs on myotome development. Embryos were coinjected with AdV-lacZ and AdV-cN/784AAA (A and B), AdV-cN/JMΔ (C and D), AdV-cN390Δ (E and F), AdV-cN/CH(−) (G and H), AdV-p120/FLf (I and J), or AdV-p120/ΔN346f (K and L). These were subjected to whole-mount X-gal staining at 72 h after injection. The triple alanine-substituted cadherin cN/784AAA had no effects on myotome morphogenesis (A and B). cN/JMΔ carrying a small deletion covering the 120ctn binding site caused the same effects as cN/JM(−) (C and D). The dominant negative cadherin cN390Δ (E and F) and the CH domain–deleted cadherin cN/CH(−) (G and H) did not affect the DV expansion of myotome, although the former perturbed segmental boundaries. The NH2 terminus–deleted p120ctn had no effect on myotome formation (K and L), whereas the full-length p120ctn affected the orientation of myofibers (I and J). Bars, 500 μm.
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fig5: Effects of expression of other cadherin or p120ctn constructs on myotome development. Embryos were coinjected with AdV-lacZ and AdV-cN/784AAA (A and B), AdV-cN/JMΔ (C and D), AdV-cN390Δ (E and F), AdV-cN/CH(−) (G and H), AdV-p120/FLf (I and J), or AdV-p120/ΔN346f (K and L). These were subjected to whole-mount X-gal staining at 72 h after injection. The triple alanine-substituted cadherin cN/784AAA had no effects on myotome morphogenesis (A and B). cN/JMΔ carrying a small deletion covering the 120ctn binding site caused the same effects as cN/JM(−) (C and D). The dominant negative cadherin cN390Δ (E and F) and the CH domain–deleted cadherin cN/CH(−) (G and H) did not affect the DV expansion of myotome, although the former perturbed segmental boundaries. The NH2 terminus–deleted p120ctn had no effect on myotome formation (K and L), whereas the full-length p120ctn affected the orientation of myofibers (I and J). Bars, 500 μm.

Mentions: Injection of AdV-cN/784AAA had no effect on myotome formation; whereas AdV-cN/JMΔ showed the same effect as AdV-cN/JM(−) (Fig. 5, A–D), thus indicating that the loss of the ability of cadherin to bind to p120ctn was not essential for the above action of the JM(−) cadherin and that the cadherin activity to affect myotome expansion must be ascribed to some other mechanisms associated with the above 17 amino acid region.


Requirement of the juxtamembrane domain of the cadherin cytoplasmic tail for morphogenetic cell rearrangement during myotome development.

Horikawa K, Takeichi M - J. Cell Biol. (2001)

Effects of expression of other cadherin or p120ctn constructs on myotome development. Embryos were coinjected with AdV-lacZ and AdV-cN/784AAA (A and B), AdV-cN/JMΔ (C and D), AdV-cN390Δ (E and F), AdV-cN/CH(−) (G and H), AdV-p120/FLf (I and J), or AdV-p120/ΔN346f (K and L). These were subjected to whole-mount X-gal staining at 72 h after injection. The triple alanine-substituted cadherin cN/784AAA had no effects on myotome morphogenesis (A and B). cN/JMΔ carrying a small deletion covering the 120ctn binding site caused the same effects as cN/JM(−) (C and D). The dominant negative cadherin cN390Δ (E and F) and the CH domain–deleted cadherin cN/CH(−) (G and H) did not affect the DV expansion of myotome, although the former perturbed segmental boundaries. The NH2 terminus–deleted p120ctn had no effect on myotome formation (K and L), whereas the full-length p120ctn affected the orientation of myofibers (I and J). Bars, 500 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199319&req=5

fig5: Effects of expression of other cadherin or p120ctn constructs on myotome development. Embryos were coinjected with AdV-lacZ and AdV-cN/784AAA (A and B), AdV-cN/JMΔ (C and D), AdV-cN390Δ (E and F), AdV-cN/CH(−) (G and H), AdV-p120/FLf (I and J), or AdV-p120/ΔN346f (K and L). These were subjected to whole-mount X-gal staining at 72 h after injection. The triple alanine-substituted cadherin cN/784AAA had no effects on myotome morphogenesis (A and B). cN/JMΔ carrying a small deletion covering the 120ctn binding site caused the same effects as cN/JM(−) (C and D). The dominant negative cadherin cN390Δ (E and F) and the CH domain–deleted cadherin cN/CH(−) (G and H) did not affect the DV expansion of myotome, although the former perturbed segmental boundaries. The NH2 terminus–deleted p120ctn had no effect on myotome formation (K and L), whereas the full-length p120ctn affected the orientation of myofibers (I and J). Bars, 500 μm.
Mentions: Injection of AdV-cN/784AAA had no effect on myotome formation; whereas AdV-cN/JMΔ showed the same effect as AdV-cN/JM(−) (Fig. 5, A–D), thus indicating that the loss of the ability of cadherin to bind to p120ctn was not essential for the above action of the JM(−) cadherin and that the cadherin activity to affect myotome expansion must be ascribed to some other mechanisms associated with the above 17 amino acid region.

Bottom Line: However, a triple alanine substitution in the JM domain, which specifically inhibited the p120ctn binding, had no effect on myotome development.Furthermore, a dominant negative N-cadherin, which had a deletion at the extracellular domain but maintained the normal cytoplasmic tail, did not affect myotome expansion; although it disrupted intersomite boundaries.Overexpression of p120ctn also did not affect myotome expansion, but it did perturb myofiber orientation.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan.

ABSTRACT
During development, the activity of cadherin cell adhesion molecules is assumed to be regulated to allow for cell rearrangement or translocation. Previous studies suggest that the juxtamembrane (JM) domain of the cadherin cytoplasmic tail, which contains the site for binding to p120ctn, has a regulatory function in this adhesion system. To study the possible role of JM domain-dependent cadherin regulation in embryonic cell rearrangement, we ectopically expressed a series of N-cadherin mutants in developing somites of chicken embryos. When a JM domain-deficient N-cadherin was expressed, the morphogenetic expansion of the myotome was strongly suppressed. However, a triple alanine substitution in the JM domain, which specifically inhibited the p120ctn binding, had no effect on myotome development. Furthermore, a dominant negative N-cadherin, which had a deletion at the extracellular domain but maintained the normal cytoplasmic tail, did not affect myotome expansion; although it disrupted intersomite boundaries. Overexpression of p120ctn also did not affect myotome expansion, but it did perturb myofiber orientation. These and other observations suggest that the JM domain of N-cadherin has a regulatory role in myotome cell rearrangement in which molecules other than p120ctn are involved. The p120ctn molecule itself seems to play a critical role in the arrangement of myofibers.

Show MeSH
Related in: MedlinePlus