Mutated E-cadherin: genomic and functional characterization in thyroid cells from the KAT family.
Members of a family of thyroid cell lines (KAT) were analyzed because they expressed a higher molecular weight (135 kd) form of E-cadherin at their surface. We found that this aberrant E-cadherin is the result of a point mutation in the exon 9 donor splice site causing a skipping of exon 9 with consequent deletion of the corresponding aminoacids on E-cadherin protein. As a spin-off, we report that the various members of the KAT family share this mutation as well as the genetic background. Furthermore we found that this mutated protein leads to disturbed cell-cell adhesion although E-cadherin is still able to mediate the formation of the cadherin/ catenin complex. We also demonstrate the presence of another cell-cell adhesion complex, formed by Pcadherin and the catenins. The latter is also not able to mediate cell-cell adhesion. Although these cells lack cell-cell adhesion they are not invasive without exogenous stimulus.
Rocha
Ana Sofia
AS
Institute of Molecular Pathology and Immunology, University of Porto, Porto, Portugal.
De Wever
Olivier
O
Moreira
Severina
S
Costa
Maria José
MJ
Vandekerckhove
Joel
J
Mareel
Marc
M
Soares
Paula
P
D001483:Base Sequence; D015820:Cadherins / Q000235:genetics* / Q000378:metabolism*; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D003598:Cytoskeletal Proteins / Q000378:metabolism; D005091:Exons; D015894:Genome, Human; D006801:Humans; D009154:Mutation; D009361:Neoplasm Invasiveness; D017354:Point Mutation; D013964:Thyroid Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D015534:Trans-Activators / Q000378:metabolism; D051178:alpha Catenin; D051176:beta Catenin
C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin