The cadherin-catenin complex is expressed alternately with the adenomatous polyposis coli protein during rat incisor amelogenesis.
E-cadherin, a calcium-dependent cell-cell adhesion molecule, is expressed in highly specific spatiotemporal patterns throughout metazoan development, notably at sites of embryonic induction. E-cadherin also plays a critical role in regulating cell motility/adhesion, cell proliferation, and apoptosis. We have used the continuously erupting rat incisor as a system for examining the expression of E-cadherin and the associated catenins [alpha-, beta-, gamma-catenin (plakoglobin) and p120(ctn)] during amelogenesis. Using immunhistochemical techniques, we observed expression of alpha-catenin and gamma-catenin in ameloblasts throughout amelogenesis. In contrast, expression of E-cadherin, beta-catenin, and p120(ctn) was strong in presecretory, transitional, and reduced stage ameloblasts (Stages I, III, and V) but was dramatically lower in secretory and maturation stage ameloblasts (Stages II and IV). This expression alternates with the expression pattern we previously reported for the adenomatous polyposis coli protein (APC), a tumor suppressor that competes with E-cadherin for binding to beta-catenin. We suggest that alternate expression of APC and the cadherin-catenin complex is critical for the alterations in cell-cell adhesion and other differentiated cellular characteristics, such as cytoskeletal alterations, that are required for the formation of enamel by ameloblasts.
Sorkin
B C
BC
The Forsyth Institute, Boston, Massachusetts, USA.
Wang
M Y
MY
Dobeck
J M
JM
Albergo
K L
KL
Skobe
Z
Z
D048868:Adaptor Proteins, Signal Transducing; D000566:Amelogenesis / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D051177:Catenins; D015815:Cell Adhesion Molecules / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000378:metabolism; D051180:Desmoplakins; D007150:Immunohistochemistry; D007180:Incisor / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin; D000095002:Delta Catenin
D048868:Adaptor Proteins, Signal Transducing; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D010750:Phosphoproteins; D011506:Proteins; C488162:Sh2b2 protein, rat; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin; D000095002:Delta Catenin; C000722355:Ctnnd1 protein, rat